Station Overview
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This is a personal weather and environmental monitoring station located in Grand Junction, Colorado, in the Grand Valley of western Colorado. The station sits at 4,646 feet elevation on the northern edge of the Uncompahgre Plateau, where terrain-channeled winds, arid climate, and dramatic temperature swings create a uniquely challenging and interesting environment to monitor. The station goes well beyond traditional weather observation, integrating meteorological, air quality, lightning, radiation, home energy, and water usage monitoring into a single unified platform. All sensors feed into a central WeeWX instance via native Davis loop packets, MQTT and HTTP, with data collected at 2 to 5 second intervals, and archived at 5-minute intervals. |
Sensor Inventory
Core Weather Station | ||
| Davis Vantage Pro2 | Temperature, humidity, barometer, wind speed & direction, rain (tipping bucket), solar radiation, UV index | |
Lightning Detection | ||
| Boltek LD-250 | Direction-finding lightning receiver with bearing and distance estimation. Dedicated industrial PC for continuous serial capture. Range up to 300 miles. | |
Air Quality — Outdoor | ||
| uRAD Monitor (Outdoor) | PM1.0, PM2.5, PM10 particulate matter; CO2 (carbon dioxide); O3 (ozone); VOC index; CH2O (formaldehyde); noise level (dB); temperature & humidity | |
Air Quality — Indoor | ||
| uRAD Monitor (Indoor) | PM0.3, PM0.5, PM1.0, PM2.5, PM10 particulate matter both μg/m³ and count; temperature & humidity | |
Radiation Detection | ||
| Geiger-Müller Tube (ESP8266) | Counts per minute (CPM), counts per second (CPS), dose rate (μSv/h - Calculated). Detects gamma and beta ionizing radiation. Built with a MightyOhm kit and an SBM-20 tube. | |
Indoor Climate Monitoring | ||
| ESP8266 — Shop Sensor | Temperature, door contact status (open/closed) | |
| ESP8266 — Garage Sensor | Temperature, door contact status (open/closed) | |
| Vantage Pro2 Console | Indoor temperature & humidity | |
Electrical Monitoring | ||
| Adafruit M0 WiFi — CT Clamps & transformer | Dual-line power (W), voltage (V), current (A), power factor, cumulative energy (kWh). Monitors both legs of 240V split-phase service. | |
Water Monitoring | ||
| RaspberryPi — Potable Water | Flow-based water usage tracking (gallons) via SDR interception of AMR utility meter broadcasts on 900 MHz ISM band. | |
Irrigation Monitoring | ||
| ESP8266 — Sprinkler Sensor | Flow (gallons), pressure (PSI). Seasonal operation. | |
System Architecture
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The station uses a fully distributed sensor architecture. Each sensor node is standalone hardware — a mix of ESP8266 microcontrollers, Adafruit M0 WiFi boards (where additional ADC channels are needed), Raspberry Pi units, dedicated industrial PCs, and commercial devices with local API access. Data flows into the central WeeWX instance through two primary channels: the native Davis loop/rec packets, and MQTT broker (Mosquitto) for real-time sensor telemetry. Other data can be translated with scripts, and submitted with MQTT. WeeWX archives all data to a local database at 5-minute intervals and generates this website via Cheetah templates. | ||
Sensor Node Hardware | ||
| ESP8266 Nodes | Shop, garage, sprinkler, irrigation water, Geiger counter. WiFi-connected, publishing to MQTT. | |
| Adafruit M0 WiFi | Electricity, publishing to MQTT | |
| Raspberry Pi | Potable water — SDR-based utility meter interception (rtl_sdr + rtlamr on 900 MHz ISM band). | |
| Industrial PC | Dedicated to the Boltek LD-250 lightning receiver. Continuous serial stream capture with no processing interruptions. | |
| Commercial (Local API) | uRAD Monitor units (indoor & outdoor air quality) polled via local network API and published to MQTT. | |
Software Stack | ||
| WeeWX 5.3.1 | Core weather engine, Davis Driver & archiver | |
| Mosquitto MQTT | Message broker for sensor telemetry | |
| MQTT WeeWX Driver | Ingests MQTT topics into WeeWX | |
| HTTP JSON Translator | Custom script for REST-based sensors | |
| Cheetah Templates | Server-side HTML generation | |
Definitions — Weather
Temperature | ||
| Temperature | Ambient air temperature measured in a shielded, ventilated enclosure (FARS). Reported in °F. | |
| Heat Index | Apparent temperature combining air temperature and relative humidity. Indicates how hot it feels when humidity slows evaporative cooling from skin. Only meaningful above ~80°F and 40% RH. | |
| Wind Chill | Apparent temperature combining air temperature and wind speed. Indicates how cold it feels due to increased convective heat loss. Uses the NWS/Environment Canada 2001 formula. Only meaningful below ~50°F with wind. | |
| Dewpoint | Temperature at which air becomes saturated and water vapor begins condensing. A dewpoint above 65°F feels muggy; below freezing indicates very dry air. Computed from temperature and relative humidity via the Magnus formula. | |
Humidity | ||
| Relative Humidity | Percentage of moisture in the air relative to the maximum it can hold at that temperature. 100% means saturated (fog, dew, or rain likely). Grand Junction's arid climate typically ranges 15–60%. | |
Barometric Pressure | ||
| Barometer | Atmospheric pressure adjusted to sea level equivalent (inHg). Rising pressure generally indicates improving weather; falling pressure suggests approaching storms. Standard sea-level pressure is 29.92 inHg. | |
| Barometer Trend | Change in barometric pressure over the previous 3 hours. Rapid drops (>0.06 inHg/3h) often precede strong weather changes. | |
Wind | ||
| Wind Speed | Instantaneous or peak gust wind speed in mph with direction in degrees (0°=N, 90°=E, 180°=S, 270°=W). | |
| Average Wind | Scalar average of wind speed over the reporting period. Treats all wind equally regardless of direction. | |
| RMS Wind | Root mean square wind speed. Gives more weight to higher speeds than simple averaging, better representing the energy content of variable winds. | |
| Vector Average | Wind averaged as a vector (preserving direction). Speed and direction reported separately. Low vector average speed with higher scalar average indicates highly variable wind direction. | |
Precipitation | ||
| Rain Total | Cumulative liquid precipitation measured by tipping bucket rain gauge. Each tip = 0.01 inches. Does not reliably measure frozen precipitation. | |
| Rain Rate | Instantaneous rainfall intensity (in/h), calculated from the interval between bucket tips. Light rain < 0.10 in/h; moderate 0.10–0.30 in/h; heavy > 0.30 in/h. | |
| Rain Days | Number of days in the period with any measurable precipitation (≥ 0.01 in). | |
Solar & UV | ||
| Solar Radiation | Global horizontal irradiance in watts per square meter (W/m²). Measures total solar energy striking a horizontal surface. Clear-sky peak at this latitude and elevation is approximately 1,100–1,350 W/m² depending on season and atmospheric clarity. | |
| UV Index | EPA-standard ultraviolet radiation index. 0–2 low, 3–5 moderate, 6–7 high, 8–10 very high, 11+ extreme. Grand Junction's elevation and clear skies regularly produce UV 8+ in summer. | |
| Evapotranspiration (ET) | Estimated water loss from soil and plant surfaces due to evaporation and transpiration. Calculated from temperature, humidity, wind, and solar radiation using the Penman-Monteith method. Critical for irrigation scheduling — when ET exceeds rainfall, supplemental watering is needed. | |
Definitions — Lightning
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Lightning data is collected by a Boltek LD-250, a direction-finding (DF) radio receiver that detects the electromagnetic impulses produced by cloud-to-ground lightning strikes. Unlike simple single-chip detectors, the LD-250 uses crossed-loop antennas to determine both bearing and estimated distance to each strike. | ||
| Strike Count | Total number of cloud-to-ground lightning strikes detected in the reporting period. | |
| Strike Distance | Estimated distance to each detected strike in miles. Accuracy is best within 100 miles; at greater distances, atmospheric propagation effects increase uncertainty. | |
| Strike Bearing | Compass direction to the detected strike in degrees from north. Used to generate the lightning maps and vector plots. | |
| Average Distance | Mean distance of all strikes in the period. A decreasing average indicates storms are approaching. | |
Activity Levels | ||
| No Activity | No strikes detected in the last hour | |
| Distant Lightning | Strikes detected beyond 100 miles in the last hour | |
| In Region | Strikes detected within 100 miles in the last hour | |
| In Area | Strikes detected within 30 miles in the last hour — be alert | |
| Nearby | Strikes detected within 10 miles in the last hour — seek shelter | |
Definitions — Air Quality
Particulate Matter | ||
| PM 0.3, 0.5 | Subcategories of ultrafine particulate matter smaller than 1.0 μm, measuring particles at the 0.3 μm and 0.5 μm size thresholds (μg/m³). These represent the finest detectable fractions of airborne particulate matter, small enough to bypass the body's respiratory defenses, penetrate deep into alveolar tissue, and translocate into the bloodstream. Sources include combustion byproducts, vehicle exhaust, and secondary aerosol formation from gas-phase chemical reactions. Tracking these sub-micron size bins provides more granular insight into the smallest and most health-relevant particles than the broader PM 1.0 measurement alone. | |
| PM 1.0 | Ultrafine particles ≤ 1.0 μm diameter (μg/m³). Small enough to penetrate deep into lung tissue and enter the bloodstream. Sources include combustion and secondary aerosol formation. | |
| PM 2.5 | Fine particles ≤ 2.5 μm diameter (μg/m³). The primary metric for health-based air quality assessment. EPA 24-hour standard is 35 μg/m³. Elevated during wildfire smoke events, which are common in western Colorado during summer and fall. | |
| PM 10 | Coarse particles ≤ 10 μm diameter (μg/m³). Includes dust, pollen, and mold spores. EPA 24-hour standard is 150 μg/m³. | |
| AQI (PM2.5) | Air Quality Index calculated from PM2.5 using EPA breakpoint tables. 0–50 Good (green), 51–100 Moderate (yellow), 101–150 Unhealthy for Sensitive Groups (orange), 151–200 Unhealthy (red), 201–300 Very Unhealthy (purple), 301+ Hazardous (maroon). | |
Gases | ||
| CO2 (Carbon Dioxide) | Measured in parts per million (ppm). Outdoor ambient is approximately 420 ppm. Indoor levels above 1,000 ppm indicate inadequate ventilation. Above 2,000 ppm can cause drowsiness and headaches. | |
| O3 (Ozone) | Ground-level ozone in parts per billion (ppb). Formed by sunlight reacting with NOx and VOCs. EPA 8-hour standard is 70 ppb. Grand Junction's altitude and sunshine make ozone a particular concern in summer. | |
| VOC Index | Volatile Organic Compounds index (unitless, nonstandard). Indicates changes in total VOC concentration relative to a baseline. Sources include paints, solvents, cleaning products, and vehicle emissions. Higher values indicate worsening air quality. | |
| CH2O (Formaldehyde) | Measured in ppb. Common indoor pollutant off-gassing from building materials, furniture, and adhesives. Outdoor levels are typically near zero. | |
Other | ||
| Noise Level | Ambient sound pressure level in decibels (dB). Provides a continuous record of environmental noise. Correlates with wind events, storms, traffic patterns, and neighborhood activity. | |
Definitions — Ionizing Radiation
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Background ionizing radiation is monitored continuously using a Geiger-Müller tube connected to an ESP8266 node using a MightyOhm kit. This detects gamma and high-energy beta radiation from natural sources (cosmic rays, terrestrial minerals, radon decay products) and provides a baseline for detecting anomalous events. | ||
| CPM (Counts Per Minute) | Raw detection rate of the GM tube. Normal background in Grand Junction is typically 15–40 CPM depending on the tube type. Sudden sustained increases may indicate a nearby radioactive source or atmospheric event. | |
| CPS (Counts Per Second) | Instantaneous count rate. CPM / 60. Useful for detecting rapid changes. | |
| Dose Rate (μSv/h) | Estimated absorbed radiation dose rate in microsieverts per hour. Converted from CPM using a tube-specific calibration factor. Normal background is 0.05–0.20 μSv/h. Annual background dose is approximately 2–3 mSv from all natural sources. | |
Definitions — Home Monitoring
Electrical | ||
| Power (W) | Real-time power consumption per line in watts. Monitored on both legs of the 240V split-phase service via current transformer (CT) clamps. Total household consumption is Line 1 + Line 2. | |
| Voltage (V) | Line voltage. Nominal is 120V per leg. Sustained readings below 114V or above 126V may indicate utility supply issues. | |
| Current (A) | Amperage draw per line. | |
| Power Factor | Ratio of real power to apparent power (0 to 1.0). A power factor of 1.0 means all power is doing useful work. Lower values indicate reactive loads (motors, compressors). Typical residential is 0.80–0.95. | |
| Energy (kWh) | Cumulative energy consumption in kilowatt-hours. Integrates instantaneous power over time. This is the same metric that is used to bill by most electric companies. | |
Water | ||
| Potable Water Usage (gal) | Domestic water consumption captured via SDR interception of the utility meter's AMR broadcast. Provides daily, weekly, monthly, and annual totals. | |
Irrigation | ||
| Irrigation Flow (gal) | Water volume through the irrigation system. Seasonal operation (typically April–October). | |
| Irrigation Pressure (PSI) | System pressure at the irrigation manifold. Useful for detecting leaks (sudden drops), clogged filters (gradual decline), or stuck valves. | |
Indoor Climate | ||
| Shop / Garage Temperature | Temperature and humidity in auxiliary buildings via ESP8266 nodes with DHT22 sensors. | |
| Door Status | Open/closed state of shop and garage doors via magnetic reed switch contacts. Displayed in the site header with color-coded status. | |
Data Statistics
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All data is archived to a local SQLite database at the station's 5-minute archive interval. The summary below reflects the primary weather database. | ||
Archive Summary | ||
| First Record | 01/01/2025 | |
Record Extremes (All-Time) | ||
| Highest Temperature | 106.3°F at 05:10 PM | |
| Lowest Temperature | -2.4°F at 06:25 AM | |
| Highest Wind Gust | 59.90 mph at 07:24 PM | |
| Wettest Day | 0.33 in at 04:05 PM | |
| Highest Barometer | 30.953 inHg at 10:20 AM | |
| Lowest Barometer | 28.940 inHg at 08:04 AM | |
Sensor Status
10 online of 10 sensors
Davis Vantage
Temp: 69.7°F
| Sig: -58 dBm
Shop
Up: 24.3 days
| Sig: -72 dBm
Garage
Up: 24.3 days
| Sig: -69 dBm
Electricity
Up: 23.7 days
| Sig: -67 dBm
Sprinkler
Up: 1.8 days
| Sig: -66 dBm
Lightning
Up: 7.9 days
Geiger
Up: 24.4 days
| Sig: -76 dBm
Water
Up: 5.9 days
Outdoor Air Quality
Up: 4.5 days
Indoor Air Quality
Up: 42.8 days
| Sig: -48 dBm
Planned & Future Improvements
Near-Term Projects | ||
| Irrigation System | Pressure sensor calibration and flow accuracy validation. Seasonal startup for 2026 growing season. Goal: automated irrigation decisions driven by ET and soil moisture data. | |
| Soil Moisture & Temperature | GroPoint TDR-based soil sensors at multiple depths (4" and 12"). TDR technology chosen for accuracy in Grand Junction's clay-heavy soils where capacitive sensors struggle. | |
| Natural Gas Monitoring | Optical pulse counter (IR reflective sensor) on the analog gas meter dial for cumulative usage tracking in therms. | |
| Water System Monitoring | Potable water pressure transducer on the supply line. Water heater tank temperature (DS18B20) and cold inlet temperature for efficiency monitoring. | |
| Radon Detection | Continuous indoor radon monitoring via pulsed ion chamber sensor (e.g., RD200M module or equivalent) with ESP8266/ESP32 integration, publishing directly to MQTT. No cloud dependency. | |
Calculated Metrics (Software) | ||
| Growing Degree Days (GDD) | Cumulative heat units for tracking crop and plant development. Calculated daily from (Tmax + Tmin) / 2 minus a base temperature (typically 50°F). | |
| Heating & Cooling Degree Days | HDD and CDD for tracking HVAC demand. Combined with electrical monitoring to calculate heating/cooling efficiency over time. | |
| Fire Weather Index | Composite index combining low humidity, high temperature, high wind, and dry fuel conditions. Particularly relevant for western Colorado's wildfire season. | |
| Feels-Like Temperature | Unified apparent temperature that automatically selects between heat index (warm conditions) and wind chill (cold conditions) to always show contextually relevant comfort level. | |
Advanced Sensors (Planned) | ||
| Ceilometer | Surplus LIDAR ceilometer (e.g., Vaisala CL31) for continuous cloud base height, cloud layer detection, and vertical visibility profiling. Sourcing from surplus/decommissioned equipment. | |
| Atmospheric Electric Field Mill | Measures ambient electric field strength at ground level (V/m). Provides a leading indicator of storm electrification before the first lightning strike. Complements the LD-250's strike detection. | |
| Disdrometer | Measures individual raindrop and hail size and velocity distribution. Classifies precipitation type (drizzle, rain, hail) and intensity in ways a tipping bucket cannot. Piezoelectric impact or optical (laser) design. | |
| Seismometer | Raspberry Shake 3D (or equivalent) in a DIY underground vault below frost line (~24") for vibration isolation. Detects local and regional seismic activity along the Uncompahgre Uplift and Bookcliffs fault structures. | |
| All-Sky Camera | Fisheye-lens camera in a weatherproof dome for 24/7 sky timelapse. Meteor detection at night, storm documentation, cloud cover quantification. | |
Data Sharing & Community
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While not currently in place, I hope that in the near future this station's data may be shared with the following programs and organizations to contribute to weather observation, climate research, and public safety in western Colorado. | ||
| CoCoRaHS | Community Collaborative Rain, Hail & Snow Network. Citizen science precipitation monitoring for the National Weather Service and state climatologists. | |
| CWOP / MADIS | Citizen Weather Observer Program, feeding into NOAA's Meteorological Assimilation Data Ingest System. Station data is incorporated into operational forecast models. | |
| NWS Grand Junction | Supplemental observation point for the NWS Western Colorado forecast office (GJT). The Grand Valley's terrain-channeled weather patterns benefit from dense observation networks. | |
About This Page
This information page provides documentation for all sensors, metrics, and systems that make up this weather and environmental monitoring station. Metric definitions are intended to help visitors understand what each measurement means and why it matters, particularly in the context of Grand Junction's unique high-desert climate.
Questions or interested in collaborating? This station is always looking to connect with researchers, forecasters, and fellow weather enthusiasts in western Colorado.