Weather in Patna in September

A hard month. September is a hard month in Patna, and worth planning around. You should expect rain on 18 days of the month, which is more days wet than dry.

September ranks 7 of 12 in Patna: past the worst of the year but short of December, which is the month to book if the dates are open.

Rain on 18 days, 5 of them heavy. Enough to need a plan B, not enough to need a plan around it. Natural fibres and a second shirt for the day. At 84% nothing dries, including you.

What the averages hide

Averages flatten a month, and this one hides a few things: 25 days top 30 °C, making the heat continuous rather than occasional. Across the twenty years measured, the hottest September day reached 35.9 °C and the coldest night fell to 20.5 °C, and the wettest single day dropped 97 mm — roughly 54% of the month's rain in one day.

September is moderately variable: 72 mm in the driest year against 329 mm in the wettest, around an average of 181 mm. Roughly two Septembers in three land near that average, and the third does something else entirely.

Wind is light at 6.8 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 84%, high enough to notice on the warm days without dominating them.

How September sits in the year

Temperatures hold steady either side: 32.7 °C in August, 31.6 here, 30.9 in October. Nothing about the timing within the month matters much. Rain is the thing that moves: October brings 12 days less of it, so pushing the dates later buys drier weather.

Daylight in September

12.3 hours of daylight, losing 0.7 hours across the month. That is between Patna's extremes of 13.7 and 10.6 hours, so days are long enough not to constrain the plan.

An inland climate

With no coast nearby, the year swings a fair way — 33.2 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage.

How busy it gets

Quiet. Few other visitors, cheaper rooms, and a real chance some seasonal operators are shut.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

September in Patna versus nearby

If Patna is one option among several, the nearby comparison is worth making. Varanasi is close enough to be a coin toss — within a degree on temperature, 2 days less rain. Kathmandu is a better bet in September — 7 °C cooler, 3 days more rain.

So: September is a compromise. December is 57 points better and is what Patna is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Patna

See all twelve months in Patna, or where else to go in September.