Take caution when comparing observations to nearby stations because the data will never match exactly. Weather stations can be sited differently and certain areas can be subject to microclimate conditions. Instrumentation can also vary between weather stations; different sensor manufacturers and styles of equipment like a cup and vane anemometer vs. a sonic anemometer will take readings differently.
Microclimates are localized atmospheric conditions that differ from those in the surrounding area. For example, most airport weather stations read higher temperatures and lower humidity as they are sited over a tarmac surface. Microclimates can be created from ground vegetation, nearby trees, moisture in wood decks, dryer vents, direct sunlight, heat radiating from a roof, etc.
Siting differences can result in different readings. Lots of personal, home weather stations are poorly sited as well. Thermometers can lack proper radiation shields and direct sun exposure leads to skewed temperature readings. Anemometers can be completely obstructed from certain directions and subject to turbulent flow around surfaces.
Try moving your AIR or SKY to different locations and analyze the data - you might be surprised at the varying microclimates and how careful siting makes for accurate data.
- Temperature reading is high: Check the siting of your AIR unit; direct exposure to sunlight will cause temperature spikes. Try moving AIR out of the sun and away from any sources that could be radiating heat. See Proper Siting & Installation for AIR.
- RH reading is high: Check surrounding environment around your AIR device for any potential sources of moisture. Try moving AIR to a drier location if the humidity remains high for long. See Proper Siting & Installation for AIR.
- Pressure reading is off: Check the AIR’s height above ground setting. This should be set as the height of the unit above the ground surface - not the elevation of your location above sea level. Open the app, go to Settings > Stations > choose your station > Manage Devices > select an AIR > edit the height above ground.
- False positives: The lightning detector in the AIR senses the small electromagnetic pulse produced by lightning. Although it will reject most triggers from non-lightning sources, it may report false positives. Possible sources of EMI (electromagnetic interference): piezo lighters, electric drill, electric motors, ignition system (cars, boilers, furnaces), appliances, fluorescent lights, TVs, light switches, high voltage wires, solenoids, motion detectors, speakers. Be sure to locate the AIR away from such sources. Re-locate your AIR if you are receiving false positives from electromagnetic interference. If you cannot identify any obvious potential interference or you are limited on siting options, subtle changes in the positioning of AIR can make a difference. Try rotating your AIR so the logo or vent slits face another direction. If you live in a 'noisy' environment you may want to disable the lightning alerts in the app or even disable the lightning sensor in AIR altogether.
- Not detecting lightning: The lightning detector is designed to detect storm activity and approximate distance; it is not capable of detecting every lightning strike. Make sure your AIR is mounted vertically and not shielded by a metal object from any direction. The lightning detection antenna inside the AIR is oriented in such a way to optimize pick up of lightning activity. Make sure to mount AIR in a vertical/upright position.
- Wind speed is incorrect: Make sure that nothing is in between the transducers and the reflective plate, such as snow, leaves, or other debris. Observe the surrounding area 360° around your SKY device; make note of any obstructions that might influence the wind flow.
Note how high above ground your SKY device is mounted. Winds are typically faster at higher altitudes. Be careful comparing data from other weather stations.
SKY uses ultra sonic transducers to measure an instantaneous wind speed - there is no inertia on the instrumentation as with a spinning cup anemometer. This method of wind speed measurement has inherent differences compared to a mechanical anemometer.
See Proper Siting & Installation for SKY.
- Unreal wind gust: Erroneously high gust readings are typically caused by water droplets or ice accumulation on the bottom reflecting plate. Insects and debris can also obstruct the ultrasonic signal path and cause incorrect readings.
- Direction incorrect: Make sure the “N” marked on the exterior of the SKY unit is pointed towards true North (not magnetic north). Also ensure the mast and SKY is level. Take a look at the transducers under the roof of the gap - if you notice anything off with any of the transducers, please contact us.
- Direction is not displayed: Sometimes direction cannot be determined during precipitation events. Check the SKY's sensor status in the Smart Weather app for a "Wind Failed" message: go to settings > station > choose your station > tap Status > scroll down to SKY's Sensor Status. If you read anything other than "OK", please contact us.
- False rain readings: Most false rain readings can result from strong winds on unstable mounts which cause the SKY to sway or shake leading to vibrations detected by the haptic rain sensor. Check your mounting situation and see if you might be able to mitigate any unwanted vibrations. Sturdy masts and added cushioning on the mount can help improve structural stability and reduce wind driven vibrations.
Birds can be another common cause of false rain. If birds become a problem, consider installing a higher perch for them to land on or use shiny, reflective stickers on the SKY and/or the mast to deter avian visitors.
- Over-reporting rain accumulation: Excess rain accumulation is inevitable on wobbly, unstable mounts, especially in in strong winds. The haptic rain sensor in SKY is a precision instrument that is very sensitive to vibrations. It is essential to install the SKY unit on a sturdy mast with secure mount. Check your mounting situation and see if you might be able to mitigate any unwanted vibrations.
- Under-reporting rain accumulation: If your sensor is under-reporting rain accumulation, please feel free to contact us.
- Not registering rain: SKY will pick up on light rain but trace amounts of precipitation are unlikely to be detected. First, try opening and closing the battery door to reboot the SKY unit. Check the SKY's sensor status in the Smart Weather app for a "Rain Failed" message: go to settings > station > choose your station > tap Status > scroll down to SKY's Sensor Status. If you read anything other than "OK", please contact us.
- Incorrect UV readings: Check that nothing is obstructing the UV sensor at the top of the SKY device; leaves, ice, debris, shadows, etc. It takes a long time to calibrate the UV/solar radiation sensor as many cloudless days of measurement are needed to perform calibration routines. If you find any abnormalities with the sensor or notice your UV readings do not improve after a month or so, please contact us.