Mumbai (Bombay) — sää kuukausittain

Mumbai has three main seasons: summer, monsoon, and winter (AKA milder summer). The best time to visit is during the winter between October and February. Humidity is also less during the winter, when the climate is pleasant; the minimum temperature is 17°C and the maximum is 30°C. Summer is from March to May, with highs in the low to mid 30s (roughly 80–90°F). It is hot and humid during this time. June to September is the monsoon season when the city is lashed by heavy rains. The city gets flooded two or three times and normal life gets disrupted during this season. Climate is humid pretty much throughout the year because the city rests on the coast.

I was in Mumbai in January. That was hella hot and humid....in January!!! A/C is absolutely a necessary thing.

Mumbai forum threads consistently rate the November-through-February stretch, including February, as the best weather window here - genuinely warm days up toward 28-30C, humid but not oppressive, with nights only dropping into the high-teens to low-20s. Posters were clear this isn't a real winter by any northern-hemisphere standard, just Mumbai's mildest, driest season relative to its intense monsoon and pre-monsoon heat. Normal, lightweight clothing works fine throughout - no need for the wool layers a February trip to Delhi might call for, with one thread specifically noting Mumbai can occasionally register cooler morning temperatures than Delhi despite the popular assumption that Delhi is always colder in winter.

March opens the pre-monsoon hot season here, which regulars date roughly mid-March to mid-June and rate progressively worse as it goes - April and May are the months to actively avoid, with March the comparatively gentler start of that run. Our row already shows real heat, 33.7C reading as 37C, though the air is genuinely dry for this city at 64.5 percent humidity, before the monsoon arrives around the 15th of June and the moisture returns with it. Rain has essentially stopped, 0.9mm across barely any days. The board's clear preference is the November-to-February window well before this, so a March trip is arriving as that better season closes. The sea is 27.9C. The record: a dew point of 18C, 11.1 hours of sun, a 17.6 kph wind and AQI 139.

Regulars are split on this month more than the general warnings suggest - most call it too hot and humid to recommend, citing the city's island geography as the reason humidity compounds the heat so heavily, while others point out the daytime high isn't far off Toronto's own summer peak and that air-conditioned rooms make it manageable. Our row backs the intensity, 34C reading as a genuinely severe 39C at 72 percent humidity, over 24.7C nights, with rain essentially absent, 0.4mm and zero rainy days. Regulars note evenings and early mornings are meaningfully more bearable than the midday stretch, and that locals routinely go about their day regardless, umbrella or scarf as sun protection rather than for rain. The sea holds 29.8C. The record: 11.7 hours of sun, an 18.4 kph wind and AQI 110.

Forum consensus on Mumbai in July is that this is the wettest stretch of the monsoon, not scattered showers: “the last week of June to end July could be intense,” with “mostly domestic flights being late or cancelled” and boat trips to Elephanta off the table because “the sea's are very rough and tides are high.” Heat doesn't let up either — regulars describe it as “very hot and muggy 35+ every day and almost 100% humidity,” the humidity doing more damage than the temperature number suggests. Our record backs the intensity: 30.6 rain days out of 31, 795mm for the month and 90% humidity — the one month here where “go anyway” is a harder sell than usual.

India-forum threads put the comfortable travel window at November through February, with November described as better than the tail of September and the start of peak tourist season - so book ahead. Mumbai's own November record is the payoff: 34.3C days and 21.7C nights, humidity around 67 percent, ten hours of sun a day, a 28.5C sea, and almost no precipitation at all, under two days on average, as the year turns toward winter. One trade-off comes with the calm: November carries some of the city's worst air of the year, with an AQI near 172, so plan outdoor sightseeing for mornings rather than the hazy afternoon.

Mumbai-forum threads rate December as one of the best months on the calendar, weather-wise - part of the November-to-February window regulars point to as the pleasant, dry season, the antidote to the sticky, stormy stretch that comes before it. Afternoons are still hot and humid, though posters say not too bad, and nights and early mornings turn genuinely pleasant. The record backs the 'not too bad' read on humidity more than the 'pleasant' one on heat: 32.2C days feeling like 35C, 19.4C nights, essentially none at one day for the whole month, and a 26.9C sea. The number forum chat skips past: AQI runs 154 here, one of the worst months of Mumbai's year for air, the trade-off for the dry season's still, cloud-free air.