Air cooler or AC in Patna? Climate verdict, tonnage, season
In Patna, eastern Gangetic humidity arrives earlier than in UP: Patna’s cooler season is short and its sticky season long, tilting purchases toward ACs despite tighter budgets. Here is what that means for the cooler-or-AC decision.
| State | Bihar |
|---|---|
| Peak temperature | ≈ 39 °C (hottest month, typical) |
| Humidity at peak | ≈ 45% RH (afternoon) |
| Hot season | April to June, oppressive humid monsoon |
| Air cooler verdict | seasonal: cooler pre-monsoon, AC after |
Cooler or AC: the Patna verdict
Patna runs on two regimes. Pre-monsoon (April to June), ~39 °C and ~45% humidity make a desert cooler superb; once the rains arrive, humidity climbs past 70% and the same cooler only adds moisture. The cost-optimal household owns both and switches by season — the AC’s dry mode carrying the sticky weeks.
If you buy an AC: the right size
Sizing for Patna: 1 to 1.5 tons for a standard bedroom, 2 tons for a hall. An inverter compressor is non-negotiable for daily use (20–40% lower seasonal consumption), and humidity makes modest sizing plus dehumidification the comfort winner. See split AC guide, tonnage rules and stabilizer advice.
Brands compared for India — Voltas, Blue Star, Lloyd, LG for ACs; Symphony, Bajaj, Crompton, Havells for coolers — on our brand pages; the air cooler guide covers desert vs tower vs personal sizing.
Frequently asked questions
Does an air cooler work in Patna?
Yes before the monsoon, no after it — Patna’s dry-then-wet season pattern (39 °C, ~45% RH at peak) is the reason. Our evaporative cooling guide explains the wet-bulb physics behind the verdict.
What AC tonnage do I need in Patna?
For Patna: 1 to 1.5 tons for a standard bedroom, 2 tons for a hall. Add margin for top-floor rooms under concrete roofs and west windows; subtract for shaded ground floors. Full rules in our tonnage guide.
Same verdict elsewhere in India: Chandigarh · Delhi · Kanpur · Lucknow · Ludhiana.