The usual limiting factor. Gust matters more than sustained wind: a multirotor
corrects continuously, and a gust that exceeds the aircraft's authority costs you
position hold and battery at the same time. Reported at 10 m above ground —
flow at altitude is normally stronger and less sheltered than the surface reading.
Temperature / dewpoint spread
The gap between air temperature and dewpoint, which is more useful than either
number alone. A spread closing toward zero means the air is saturating: fog or low
stratus is forming, and visibility can collapse quickly. A small spread near or below
freezing also indicates icing potential. Highlighted at 4 °F or less.
Density altitude
The altitude the air feels like to a rotor, after correcting field
elevation for pressure and temperature. High density altitude thins the air, so rotors
generate less thrust: climb rate drops, payload margin shrinks, and endurance falls.
On a hot afternoon at these elevations it commonly runs thousands of feet above the
ground you are standing on, which is the failure mode that surprises pilots trained
at lower elevation. Computed for the project site, not the reporting station.
Highlighted when it exceeds site elevation by 2,000 ft or more.
Ceiling & maximum altitude
Ceiling is the lowest broken or overcast layer; scattered and few layers are not
ceilings. Which cloud rule applies depends on how you are operating, and the badge
beside the coordinates shows which set this page is using.
COA / part 91 (default). COA 2025-WSA-16323 authorizes Class G
operations at or below 1,199 ft AGL. Under 14 CFR 91.155, Class G
at or below 1,200 ft AGL by day requires 1 statute mile visibility and
remaining clear of clouds, so the ceiling itself becomes the cap when it falls below
1,199 ft. Night minimums are higher.
Part 107. 400 ft AGL, 3 statute miles, and 500 ft below
the clouds — add rule=107 to the URL to use these instead.
Either way the COA altitude applies in Class G only, and this page does not
check which airspace the site sits in. Override the ceiling with the alt
parameter.
Visibility
Threshold follows the rule set in force: 1 statute mile for daytime
Class G under 91.155, 3 statute miles under 107.51. Highlighted below the
applicable figure.
Weather minimums inside a TFR
The COA waives 91.155 only for operations conducted within a 91.137 TFR, where the
incident or on-scene commander is responsible for airspace segregation and
deconfliction between manned and unmanned aircraft. Outside a TFR the standard
minimums above apply, and this page always displays the unwaived thresholds.
Precipitation
Accumulation in the past hour at the reporting station. Most airframes are not
rated for flight in precipitation, and water on the lens ends a mapping mission
regardless of what the aircraft tolerates.
Kp index
Planetary geomagnetic activity, 0–9. Elevated Kp disturbs the ionosphere and
degrades GNSS accuracy, which matters more for PPK and RTK survey work than for
ordinary flight: it lengthens time to fix and can leave you with float rather than
fixed solutions. Kp 5 and above is storm level and is highlighted. Below about
4 it is not worth thinking about.
Sun & lighting
Under the COA these times are a lighting trigger, not a hard stop. The Certificate
of Waiver requires anti-collision lighting for civil twilight and night operations to
increase the conspicuity of the aircraft, and the system must be operational at all
times, day or night, unless operating in a TFR — the CoW waives 91.209(a)(1)
only inside a TFR. A reminder appears here when the current time falls outside sunrise
to sunset. Sun angle also drives shadow length: low-sun imagery produces long shadows
and weaker tie points in photogrammetric processing. Computed from the site
coordinates and today's date.
Before you fly
Not weather, but on the same checklist. The COA requires a Distant (D) NOTAM not
less than 24 hours and not more than 72 hours in advance of routine operations,
cancelled when the operation is complete; first responder and prescribed fire
operations may file as soon as practicable. Airport standoffs are 5 NM from a
towered airport, 3 NM from an airport with a published instrument procedure,
2 NM otherwise, and 2 NM from a heliport. MTR and SUA deconfliction is the
operator's responsibility.
Forecast sections
Watch-outs and the day/night outlook come from the National Weather Service
gridded forecast for the project coordinates. Current conditions come from the nearest
station that is reporting, which may be a considerable distance and elevation away.