Patna climate — normals and trends
Patna (India) has a hot-summer mediterranean climate (Csa) under the Köppen-Geiger classification. Its mean annual temperature is 25.7 °C and it receives 1,147 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is May (32.3 °C on average) and the coldest is January (16.3 °C). Rainfall peaks in July.
Patna averages 0 frost days, 226 hot days (≥ 30 °C) and 118 rainy days per year.
Patna has warmed by +0.7 °C between 1940 and 2025, or +0.08 °C per decade. This trend is statistically significant.
The hottest day of the period reached 46.8 °C (on 29 May 1957) and the coldest 3.4 °C (on 9 January 2013).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
PatnaBihar
- coords
- 25.59°, 85.14°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
25.7°C
Average daily high
31.3°C
Average daily low
21.0°C
Annual rainfall
1,147mm
Sunshine / day
10.2h
Mean relative humidity
67%
Average peak wind
14.6km/h
Seasonal range
16.0°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
226 d/yr
Rainy days (≥ 1 mm)
118 d/yr
Annual snowfall
0.0 cm
Average feels-like high
33.8 °C
Average feels-like low
22.9 °C
Average peak gust
29.8 km/h
Tropical nights (≥ 20 °C)
220 d/yr
Solar radiation
18.3 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+0.7 °C
since 1940
+0.1 °C per decade · r² = 0.13 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
46.8 °C
29 May 1957
Coldest day
3.4 °C
9 January 2013
Wettest day
336 mm
30 June 1996
Windiest day
44.5 km/h
23 September 1962
Strongest gust
81.0 km/h
8 August 1979
Hottest feels-like
50.7 °C
29 May 2024
Coldest feels-like
0.8 °C
9 January 2013
Sunniest day
13.0 h
4 June 1958
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 21.7 °C | -1.4 °C | 1 mm | -20 mm |
| Feb | 27.6 °C | +0.9 °C | 1 mm | -17 mm |
| Mar | 32.6 °C | -0.3 °C | 8 mm | -8 mm |
| Apr | 36.2 °C | -1.6 °C | 31 mm | +13 mm |
| May | 36.4 °C | -2.2 °C | 49 mm | +13 mm |
| Jun | 35.9 °C | -0.6 °C | 131 mm | -23 mm |
| Jul | 33.3 °C | +0.7 °C | 278 mm | -39 mm |
| Aug | 32.4 °C | +0.2 °C | 335 mm | +58 mm |
| Sep | 33.1 °C | +1.4 °C | 244 mm | +39 mm |
| Oct | 30.7 °C | 0.0 °C | 238 mm | +171 mm |
| Nov | 28.0 °C | -0.3 °C | 1 mm | -8 mm |
| Dec | 21.8 °C | -2.8 °C | 0 mm | -10 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Patna?
Patna has a hot-summer mediterranean climate (Köppen Csa). Over 1940-2025, the average annual temperature is 25.7 °C and it receives 1,147 mm of precipitation per year.
What is the hottest day ever recorded in Patna?
The hottest day measured in Patna between 1940 and 2025 was 29 May 1957, reaching 46.8 °C.
What is the coldest day in Patna?
The coldest day measured in Patna between 1940 and 2025 was 9 January 2013, at 3.4 °C.
Does it snow in Patna?
Almost never: Patna sees virtually no snow, with about 0 frost days per year.
Has the climate of Patna warmed?
Yes: Patna warmed by +0.7 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Patna?
The wettest day measured in Patna between 1940 and 2025 was 30 June 1996, with 336 mm of rain in 24 hours.
What was the windiest day in Patna?
The windiest day measured in Patna between 1940 and 2025 was 23 September 1962, with winds reaching 44.5 km/h.
What is the warmest month in Patna?
The warmest month in Patna is May (32.3 °C on average); the coldest is January (16.3 °C).
How much does it rain in Patna?
Patna receives on average 1,147 mm of precipitation per year, spread over about 118 rainy days.
Is it sunny in Patna?
Patna gets on average 10.2 hours of sunshine per day, roughly 3,723 hours per year over 1940-2025.
Are there tropical nights in Patna?
Yes: Patna has on average 220 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Patna?
In Patna, between 1940 and 2025, the highest apparent temperature reached 50.7 °C on 29 May 2024, and the lowest was 0.8 °C on 9 January 2013.
Compare Patna with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Patna