#meteorology

The Beaufort wind scale as an API, computed locally and deterministically. The classify endpoint turns a measured wind speed — in metres per second, kilometres per hour, knots, miles per hour or feet per second — into its Beaufort force (0 calm to 12 hurricane), with the descriptive name (light breeze, gale, storm …), the corresponding sea state and the mean open-sea wave height, plus the speed expressed in every unit. The force endpoint looks up a Beaufort number and returns its wind-speed range in all units, its description, sea condition and wave height. The convert endpoint converts a wind speed across metres per second, kilometres per hour, knots, miles per hour and feet per second and reports the matching Beaufort force (1 knot = 0.514444 m/s). Speeds use the standard 10-metre reference height and wave heights are open-sea means. Everything is computed locally and deterministically, so it is instant and private. Ideal for sailing, marine, aviation, drone, weather and outdoor app developers, wind-warning and sea-state tools, and meteorology education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is the Beaufort wind scale; for the feels-like wind chill use a feels-like API and for live wind observations a weather data API.

api.oanor.com/beaufort-api

Feels-like (apparent) temperature meteorology as an API, computed locally and deterministically. The wind-chill endpoint computes how cold the air feels when wind carries body heat away, using the Environment Canada formula WC = 13.12 + 0.6215·T − 11.37·V^0.16 + 0.3965·T·V^0.16 from the air temperature (°C) and wind speed (km/h), valid at 10 °C or below with wind of at least 4.8 km/h. The heat-index endpoint computes how hot it feels in warm, humid air with the US National Weather Service Rothfusz regression from temperature and relative humidity, since high humidity slows sweat evaporation, with the low-/high-humidity adjustments. The apparent-temperature endpoint computes the Australian Bureau of Meteorology apparent temperature, AT = Ta + 0.33·e − 0.70·ws − 4.00, which combines the warming effect of humidity (through the vapour pressure e) and the cooling effect of wind (ws in m/s) in a single feels-like value. Temperatures are in °C (Fahrenheit also returned), humidity in %, wind in km/h for wind chill and m/s for apparent temperature. Everything is computed locally and deterministically, so it is instant and private. Ideal for weather, outdoor-activity, sports, smart-home and wearable app developers, comfort and safety tools, and meteorology education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is the feels-like temperature calculator; for the occupational WBGT heat-stress index use a WBGT API and for live weather observations a weather data API.

api.oanor.com/feelslike-api

International Standard Atmosphere (ISA) maths as an API, computed locally and deterministically. The properties endpoint gives the air temperature, pressure, density and speed of sound at any altitude from sea level to 20 km — using the standard troposphere lapse rate (T = T0 − 0.0065·h) and the isothermal lower stratosphere above 11 km — along with the density, pressure and temperature ratios relative to sea level. The density-altitude endpoint computes the density altitude — the ISA altitude with the same air density — from a pressure altitude and the actual outside-air temperature, the figure pilots use because heat and low pressure rob an aircraft of lift, engine power and propeller thrust; it also reports the ISA temperature deviation. The pressure-altitude endpoint turns a barometric reading (in hectopascals or pascals) into the pressure altitude, the ISA altitude at which the standard pressure equals your reading. Altitudes accept metres or feet, temperature °C or kelvin. Everything is computed locally and deterministically, so it is instant and private. Ideal for aviation, drone, ballooning, HVAC and meteorology app developers, flight-planning and performance tools, and physics education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is the ISA atmospheric model; for the acoustic and relativistic Doppler effect use a Doppler API.

api.oanor.com/atmosphere-api

Coriolis and centrifugal forces in a rotating frame as an API, computed locally and deterministically. The coriolis endpoint computes the Coriolis acceleration a = 2·Ω·v·sin(θ) and, given a mass, the Coriolis force F = m·a, for an object moving at a speed in a frame rotating at a given rate — supplied directly in radians per second, as rpm, or as planet=earth (Ω = 7.2921×10⁻⁵ rad/s) — with the angle taken as the latitude for motion over the Earth or an explicit angle to the rotation axis. The centrifugal endpoint computes the centrifugal acceleration a = ω²·r = v²/r and force from a radius and an angular speed (rad/s, rpm or a tangential velocity), and reports the g-force, handy for centrifuges, rotating machinery and amusement rides. The earth endpoint gives the rotation effects at a latitude: the Coriolis parameter f = 2·Ω·sin(lat), the inertial-oscillation period 2π/|f|, the eastward speed of the Earth's surface, the centrifugal acceleration, and which way moving objects are deflected (right in the Northern Hemisphere, left in the Southern). Everything is computed locally and deterministically, so it is instant and private. Ideal for meteorology, oceanography and geophysics tools, centrifuge and rotating-machinery design, ballistics and physics-education apps. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is rotating-frame dynamics; for projectile and SUVAT kinematics use a physics API and for banked-curve cornering use a banked-curve API.

api.oanor.com/coriolis-api

Wet Bulb Globe Temperature (WBGT) heat-stress index as an API, computed locally and deterministically. WBGT is the standard occupational and athletic heat-stress measure (ISO 7243). The wbgt endpoint computes the true index from measured thermometer readings: outdoors in the sun WBGT = 0.7·Tnwb + 0.2·Tg + 0.1·Tdb, and indoors or in the shade WBGT = 0.7·Tnwb + 0.3·Tg, from the natural wet-bulb, globe and dry-bulb temperatures, and returns the heat-stress flag and work-rest and hydration guidance. The estimate endpoint gives an approximate shade WBGT from just the air temperature and relative humidity using the Bureau of Meteorology approximation — e = (rh/100)·6.105·exp(17.27·T/(237.7+T)); WBGT ≈ 0.567·T + 0.393·e + 3.94 — for when you do not have a globe or wet-bulb thermometer. The flag endpoint classifies any WBGT value (°C or °F) into a heat-stress category — green, yellow, red or black — with the recommended work-rest cycle and water intake. Everything is computed locally and deterministically, so it is instant and private. Ideal for occupational-safety and industrial-hygiene tools, sports, military and outdoor-event planning, and environmental-monitoring apps. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is the WBGT heat-stress index; for the NWS heat index, wind chill and dew point use a weather-formulas API.

api.oanor.com/wbgt-api

Meteorological formulas as an API — the derived weather figures, computed from your own readings, with no data feed or key needed. The wind-chill endpoint gives the "feels like" cold using the Environment Canada formula in metric (°C, km/h) or the US NWS formula in imperial (°F, mph), and flags when the reading is outside the valid range. The heat-index endpoint gives the apparent temperature from heat and humidity using the NWS Rothfusz regression with the standard low- and high-humidity adjustments. The dew-point endpoint uses the Magnus formula to turn temperature and relative humidity into the dew point, and also returns the vapour pressure and the absolute humidity. The beaufort endpoint maps a wind speed (m/s, km/h, mph or knots) to its Beaufort force and description, or a force back to its speed range. Everything is computed locally and deterministically, so it is instant and private. Ideal for weather apps and dashboards, agriculture and HVAC, marine and aviation, and outdoor and safety tools. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 5 endpoints. This computes weather formulas from your own readings; for live forecasts and observations use a weather data API.

api.oanor.com/weathercalc-api

Decades of historical weather for any location on Earth, from 1940 to the present. Pull daily records — temperature highs, lows and means, apparent temperature, precipitation, rain, snowfall, wind speed, gusts and direction — or an hourly series with temperature, humidity, precipitation, wind, pressure and cloud cover, or a period summary with mean temperature, the hottest and coldest day, total precipitation and wet-day counts. Global coverage from the ERA5 reanalysis archive via Open-Meteo, delivered as tidy JSON through a fast, reliable API. Ideal for agriculture and energy, insurance and risk, climate research, construction and travel planning.

api.oanor.com/weatherhistory-api