VFR Flight Weather Planner for New England Pilots

WhenVFR gives general aviation pilots a 14-day go/no-go forecast for New England airports. Pick your home base, set your personal minimums, and see at a glance which days and times are worth flying — without scrolling through raw METAR and TAF reports.

How the score works

Every hour at every airport gets a 0–100 score built from the four factors that matter for a VFR decision:

• Ceiling — cloud base height above ground. Low ceilings mean MVFR or IFR conditions; 5,000 ft and up is a comfortable VFR day.
• Visibility — statute miles you can see. Under 3 SM is IFR; under 5 is marginal.
• Crosswind component — wind angle relative to the runway. Computed against each airport's actual runway headings.
• Gusts — wind variability. Gusts more than 10 kt over sustained wind get penalized on a tiered scale.

Scores combine those against your personal minimums. Use the Beginner, Seasoned, or Maverick presets for quick setup, or drag the sliders to match how you actually fly.

Data sources

WhenVFR layers multiple weather and geo sources, each picked for a specific role. The scoring engine prefers them in this order — actual observations beat human forecasts, which beat statistical models, which beat raw model output.

METAR aviationweather.gov

Current observed conditions at each airport, updated hourly. Drives the score for the present hour wherever an airport reports.

TAF aviationweather.gov

Terminal Aerodrome Forecast — the human-written aviation forecast issued by NWS meteorologists. Authoritative for ceiling and visibility 24–30 hours out at TAF-issuing airports. If a TAF period has just ended we persist it up to 3 hours and label the cell TAF~.

GFS-MOS mesonet.agron.iastate.edu

Statistical post-processing of the GFS model, mirrored by Iowa Environmental Mesonet. Same MAV bulletin ForeFlight uses past the TAF window. Fills in the 24–84 hour range when no METAR or TAF is available.

NWS gridded forecast api.weather.gov

National Weather Service hourly gridpoint forecast. Used primarily for gust forecasts (the most calibrated wind data we have) and as a fallback when neither TAF nor MOS covers an hour.

GFS via Open-Meteo open-meteo.com

Raw Global Forecast System output, served as a free JSON API. Provides the long-range 14-day outlook — cloud cover, visibility, precipitation probability, and 850 hPa winds for en-route segments. When this is the only source, ceiling is inferred from cloud cover and visibility.

Airport database aviationweather.gov

Runway alignments, ICAO/FAA codes, and lat/lon for every US airport. Drives the crosswind math and the "Add an airport" lookup. Grass strips that AviationWeather doesn't index fall back to manual coords baked into the destinations data.

Photon (Komoot) photon.komoot.io

Open-source OpenStreetMap-based geocoder, enriched with Wikidata POIs. Resolves walkable-spot names (Kimball Farm, Bob Lobster, Sunset Pub) to coordinates on the Fun destinations page, so the 🚶 Walk button routes from the airport to the actual restaurant or beach instead of a search page.

Airports covered

Coverage focuses on New England general aviation fields, including Norwood Memorial (KOWD), Hyannis (KHYA), Nantucket Memorial (KACK), Martha's Vineyard (KMVY), Portsmouth (KPSM), Bar Harbor (KBHB), Portland Jetport (KPWM), Block Island (KBID), New Bedford Regional (KEWB), Plymouth Municipal (KPYM), and Fitchburg Municipal (KFIT). Pick a home airport and the planner shows nearby destinations, waypoints along the route, and en-route conditions for each flight.

Add your own airports

Don't see your home field in the list? Use the + Add row at the bottom of the airport table to search for any US airport by ICAO code or name and add it to your view. Custom airports stick around between visits and get the same forecast treatment as built-in ones.

Feedback

WhenVFR is actively being improved. If something looks off, a forecast doesn't match what you're seeing on ForeFlight or 1800wxbrief, or you want an airport or feature added — drop a note in the Feedback box below the forecast grid. Anything helps.

Who it's for

Private pilots, student pilots, and CFIs planning VFR cross-countries, currency flights, and $100 hamburger runs. WhenVFR is free and browser-based — nothing to install, no login required.