Weather Forecast for Delhi

"Feels like" is the apparent temperature your body perceives once humidity, wind, and sunlight are factored in. In hot, humid weather it uses a heat-index formula — sweat evaporates slower when the air is already wet, so 32 °C at 80% humidity feels closer to 40 °C. In cold, windy weather it uses wind-chill — moving air strips heat from skin faster than still air. The actual air temperature is unchanged; only the physiological load is different.

Humidity (more precisely, relative humidity) is the amount of water vapour in the air expressed as a percentage of the maximum the air can hold at that temperature. 100% means the air is saturated and dew or fog can form; 40–60% is broadly comfortable; below 30% feels dry. Because warm air can hold more water than cold air, the same absolute moisture reads as a lower humidity on a hot afternoon and a higher humidity at night.

Wind speed is the steady, averaged value over a short interval (typically 10 minutes). A wind gust is the brief peak within that interval — a sudden burst lasting only a few seconds. The dashboard shows both because a 15 km/h average with 45 km/h gusts is a very different outdoor experience from a steady 15 km/h. Gusts are what knock over umbrellas, scooters, and loose objects.

Under 20 km/h is calm to light breeze and comfortable for most outdoor activity. 20–40 km/h is a fresh-to-strong breeze — cycling and umbrellas become awkward. 40–60 km/h is a near-gale; small branches break and walking against the wind is tiring. Above 60 km/h is a gale and outdoor work should be paused. Above 90 km/h is storm-force and considered dangerous.

AQI (Air Quality Index) is a single number from 0 to 500 that summarises how polluted the air is, computed from eight pollutants — PM2.5, PM10, NO₂, SO₂, CO, O₃, NH₃, and Pb. India's system was published by the Central Pollution Control Board (CPCB) in 2014. The reported AQI is the worst sub-index among the pollutants measured, so a high PM2.5 reading alone can drive the headline number even if other pollutants are clean.

India's CPCB bands: 0–50 Good (no precaution), 51–100 Satisfactory (minor discomfort for the very sensitive), 101–200 Moderate (people with asthma or heart conditions should limit prolonged exertion), 201–300 Poor (breathing discomfort for most on long exposure), 301–400 Very Poor (respiratory illness on prolonged exposure — mask outdoors), 401–500 Severe (serious health impact even with light activity — avoid outdoor exercise).

PM2.5 refers to particulate matter smaller than 2.5 micrometres — roughly 1/30th the width of a human hair. The particles are small enough to bypass the nose and throat and lodge deep in the lungs, and the finest fractions can cross into the bloodstream. Long-term exposure is linked to asthma, reduced lung function in children, heart disease, and stroke. PM2.5 is usually the dominant driver of bad AQI days in Indian cities, especially in winter.

Each hourly slot shows the predicted condition (sunny, cloudy, rain), temperature, and precipitation probability for that hour. Scan left-to-right to see how the day evolves — whether a rain band is arriving in the afternoon, when the peak heat lands, or when winds pick up. Hourly forecasts are most reliable for the next 12–24 hours; beyond that, daily summaries are more trustworthy than hour-specific predictions.

It is the model's estimated probability that measurable rain (typically ≥ 0.1 mm) falls at the forecast location during the time window. 40% does not mean "40% of the area gets rain" or "rain for 40% of the hour". It means: if the same atmospheric setup repeated 10 times, rain would occur about 4 of those times. Under 20% is essentially "unlikely"; over 70% is "expect it".

Day 1–2 forecasts are typically 90%+ accurate for temperature and condition category. Accuracy drops with each added day: day 5 is around 75%, and day 7 is closer to 65%. Rain timing and intensity degrade faster than temperature. Treat the back end of a 7-day strip as direction of travel — "rain expected mid-week" — rather than a precise hour-by-hour prediction.

Weather models re-run on a fixed cadence (typically every 1, 3, or 6 hours) using the latest satellite, radar, balloon, and surface observations. Each new run nudges the prediction as fresh data narrows the uncertainty. The dashboard pulls the freshest available model output, so a forecast that said "30% rain at 4 pm" this morning may read "60% rain at 5 pm" by noon — not because the earlier forecast was wrong, but because newer observations have sharpened it.

The UV Index is a 0–11+ scale of how strong the sun's ultraviolet radiation is at ground level. 0–2 Low (safe), 3–5 Moderate (sunglasses + SPF 30 if outdoors more than an hour), 6–7 High (skin can burn in 20–30 minutes — SPF 30+ and a hat), 8–10 Very High (burn in 15 minutes — seek shade between 10 am and 4 pm), 11+ Extreme (burn in under 10 minutes). UV is highest around solar noon and at high altitude, regardless of air temperature.

Earth's axis is tilted 23.5° relative to its orbit around the Sun. As Earth moves through the year, the Sun's apparent path across the sky tilts north in summer and south in winter, lengthening or shortening the daylight period. Around the solstices (around June 21 and December 21) the shift is slow — only seconds per day. Around the equinoxes (around March 21 and September 23) the shift is fastest — over a minute per day. Your longitude also offsets the clock time of local noon, which is why sunrise in Kolkata is roughly an hour earlier than in Mumbai.