Arrah climate
Arrah (Bihar, India) has a hot-summer Mediterranean climate (Köppen Csa). The average temperature over the year is 26 °C79 °F, and about 968 mm38 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Arrah climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin |
|---|---|---|---|---|
| Jan | 2374 | 847 | 1660 | 110.5 |
| Feb | 2883 | 1253 | 2068 | 140.5 |
| Mar | 3595 | 1763 | 2679 | 90.4 |
| Apr | 41105 | 2475 | 3290 | 140.5 |
| May | 42108 | 2882 | 3595 | 461.8 |
| Jun | 40104 | 3086 | 3595 | 1475.8 |
| Jul | 3493 | 2781 | 3187 | 27311 |
| Aug | 3290 | 2679 | 2985 | 2299.0 |
| Sep | 3189 | 2576 | 2882 | 1736.8 |
| Oct | 3187 | 2068 | 2578 | 471.9 |
| Nov | 2781 | 1458 | 2170 | 10.1 |
| Dec | 2474 | 1049 | 1762 | 30.1 |
| Year | 42108 | 847 | 2679 | 96838 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 50% | 32% | 3.1 | 10:42 |
| Feb | 43% | 24% | 4.5 | 11:16 |
| Mar | 31% | 24% | 5.8 | 11:57 |
| Apr | 25% | 26% | 6.5 | 12:44 |
| May | 31% | 36% | 6.5 | 13:23 |
| Jun | 48% | 62% | 5.6 | 13:43 |
| Jul | 76% | 80% | 4.6 | 13:35 |
| Aug | 83% | 76% | 4.8 | 13:02 |
| Sep | 84% | 61% | 4.7 | 12:16 |
| Oct | 73% | 26% | 4.5 | 11:30 |
| Nov | 62% | 15% | 3.8 | 10:51 |
| Dec | 56% | 24% | 3.0 | 10:33 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Arrah is like
The warmest month is May, with an average high of 42 °C108 °F and a low of 28 °C82 °F. The coldest is January, when highs average 23 °C74 °F and lows 8 °C47 °F. Seasons are strongly marked: the warmest month is on average 19.6 °C35.3 °F warmer than the coldest.
Annual precipitation is moderate at about 968 mm38 in. The wettest three-month stretch is July–September, which brings 70% of the annual total. Months with less than 20 mm0.8 in on average: November–April. The wettest month is July (273 mm11 in), the driest is November (1 mm0.1 in).
Relative humidity ranges from 25% in April to 84% in September. The clearest skies (lowest average cloud amount, 15%) are typical of November. Average wind speed near the ground ranges from 4 km/h (3 mph) in November to 10 km/h (6 mph) in June. Daylight lasts from about 10.6 hours in December to 13.7 hours in June.
Best time to visit Arrah
Based on these averages, the most comfortable months for sightseeing and outdoor activities are November–February: average highs of 23 °C74 °F to 28 °C83 °F with 1 mm0.1 in to 14 mm0.5 in of precipitation per month.
The most challenging month is July, which is hot, with average highs of 34 °C93 °F, very wet (273 mm11 in) and humid (76% relative humidity).
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Arrah
- Winter (December–February) — highs 2374 to 28 °C83 °F, lows 847 to 12 °C53 °F, about 9 mm0.4 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an extra layer for the cooler mornings and evenings.
- Spring (March–May) — highs 3595 to 42 °C108 °F, lows 1763 to 28 °C82 °F, about 23 mm0.9 in of precipitation a month. Pack very light, breathable clothing, a sun hat and plenty of water.
- Summer (June–August) — highs 3290 to 40 °C104 °F, lows 2679 to 30 °C86 °F, about 216 mm8.5 in of precipitation a month. Pack very light, breathable clothing, a sun hat and plenty of water and a good rain jacket or umbrella and quick-drying shoes.
- Autumn (September–November) — highs 2781 to 31 °C89 °F, lows 1458 to 25 °C76 °F, about 74 mm2.9 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses.
How Arrah compares
Compared with Patna, about 48 km to the east, Arrah has practically the same average temperature and receives a similar amount of precipitation.
Of the 382 places in India covered by World Climates, Arrah is the 177th warmest by annual mean temperature and the 191st wettest by annual precipitation. See all of them on the India climate page.
Places in other countries with the most similar temperature and rainfall pattern: Janakpur (Nepal, Cwa), Birgañj (Nepal, Cwa) and Lahan (Nepal, Cwa).
Nearby places
- Chapra 26 km · 26 °C79 °F · 1,041 mm41 in
- Patna 48 km · 26 °C79 °F · 994 mm39 in
- Jahanabad 50 km · 26 °C79 °F · 1,013 mm40 in
- Siwan 80 km · 26 °C79 °F · 1,012 mm40 in
- Madhurampur Dehri 80 km · 26 °C79 °F · 1,001 mm39 in
- Gaya 91 km · 26 °C79 °F · 1,013 mm40 in
- Sasaram 94 km · 27 °C80 °F · 913 mm36 in
- Bihar Sharif 95 km · 26 °C79 °F · 1,013 mm40 in
Frequently asked questions
What is the warmest month in Arrah?
May is the warmest month in Arrah, with an average high of 42 °C (108 °F) and an average low of 28 °C (82 °F).
What is the coldest month in Arrah?
January is the coldest month, with an average high of 23 °C (74 °F) and an average low of 8 °C (47 °F).
When does it rain the most in Arrah?
July is the wettest month with about 273 mm (10.8 in) of precipitation; November is the driest with about 1 mm (0.1 in).
What is the best time to visit Arrah?
Judging by long-term averages, the most comfortable months are November–February.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.