- Patna’s climate ranges from hot, dry summers (up to 38 °C) to cool winters (as low as 10 °C).
- The monsoon delivers most of the city’s ~1,100 mm annual rainfall between June and September, peaking in July.
- October‑February are the most comfortable months for visitors, with moderate temperatures and low humidity.
- Winter inversions can raise PM2.5 levels above 150 µg/m³, while monsoon rains improve air quality.
- During summer, stay hydrated, wear breathable clothing, and avoid midday outdoor exposure.
The weather in Patna is characterized by a hot, dry summer, a humid monsoon, and a cool winter. Average temperatures range from 10 °C (50 °F) in January to 38 °C (100 °F) in May, while most rainfall falls between June and September. The most pleasant visiting period is from October to February, when temperatures are moderate and humidity is low.
What is the overall climate of Patna?
Patna lies in the Indo‑Gangetic plain at an elevation of 53 m (174 ft) and experiences a tropical wet‑and‑dry (Aw) climate according to the Köppen system. The city endures three distinct seasons: a scorching pre‑monsoon summer, a wet monsoon season, and a mild winter. Seasonal shifts are driven by the South Asian monsoon and the retreat of the western disturbances that bring cooler air in winter.
How does temperature vary throughout the year?
Monthly average maximum and minimum temperatures illustrate the temperature swing across Patna.
| Month | Avg High (°C) | Avg Low (°C) | Avg Rainfall (mm) |
|---|---|---|---|
| January | 22 | 9 | 5 |
| February | 26 | 12 | 7 |
| March | 32 | 18 | 8 |
| April | 37 | 23 | 12 |
| May | 38 | 27 | 30 |
| June | 36 | 27 | 150 |
| July | 34 | 26 | 210 |
| August | 33 | 26 | 190 |
| September | 33 | 25 | 170 |
| October | 30 | 21 | 55 |
| November | 26 | 15 | 20 |
| December | 22 | 11 | 10 |
The data shows that May is the hottest month, with average highs of 38 °C, while January is the coolest, with lows around 9 °C. Rainfall spikes sharply from June to September, peaking in July at about 210 mm, confirming the monsoon’s dominance.
When does the monsoon season occur?
Patna’s monsoon arrives in early June and withdraws by the end of September. During this four‑month window, humidity often exceeds 80 % and daily thunderstorms are common. The most intense rainfalls are recorded in July and August, when the city can receive more than 150 mm in a single month.
What are the best months to visit Patna?
For tourists, October through February offers the most comfortable climate. Daytime temperatures stay between 20 °C and 28 °C, and rainfall drops below 30 mm per month, making outdoor sightseeing and riverfront walks pleasant. Nighttime can be cool in December, so a light jacket is advisable.
How to prepare for Patna’s extreme heat?
If you must travel during the pre‑monsoon summer (April‑June), follow these practical steps:
- Drink at least 2‑3 litres of water per day to stay hydrated.
- Wear light, breathable fabrics such as cotton or linen.
- Apply sunscreen with SPF 30+ and reapply every two hours.
- Limit outdoor activities to early morning or late evening when temperatures are lower.
- Prefer air‑conditioned transport or shaded routes for longer journeys.
Is Patna’s air quality affected by its weather?
Air quality in Patna typically worsens in winter when temperature inversions trap pollutants near the surface, leading to PM2.5 levels that can exceed 150 µg/m³. Conversely, the monsoon rains help disperse dust and lower particulate concentrations, although high humidity can increase the perception of smog.
Quick climate facts at a glance
- Average annual rainfall: ~1,100 mm.
- Highest recorded temperature: 45 °C (2016).
- Lowest recorded temperature: 4 °C (2002).
- Average relative humidity: 60 % annually.
- Sunlight hours per year: about 2,800 h.
Frequently Asked Questions
What is the typical daytime temperature in Patna during early May?
In early May, Patna usually experiences daytime highs around 38 °C (100 °F) with evening temperatures near 27 °C (81 °F), marking the peak of the pre‑monsoon heat.
When does Patna have the lowest relative humidity?
The lowest humidity levels occur in winter, especially in December and January, when relative humidity often drops to 45‑55 %.
How much rainfall does Patna receive in August?
Patna receives roughly 190 mm of rain in August, making it one of the wettest months of the monsoon season.
Is it safe to travel to Patna during the monsoon season?
Travel is generally safe, but heavy downpours can cause road water‑logging; plan indoor activities and allow extra time for commuting.
What clothing is advisable for Patna’s winter evenings?
Light woolens, sweaters, and a wind‑proof jacket are recommended for winter evenings when temperatures can fall to 10‑12 °C.