Last updated 24 September 2026
The usual answer is October to March, and it is half right. Those months have the comfortable weather, but they also contain Delhi's worst air of the year — November and December routinely sit in the hazardous range, and January fog can close the airport and hide the Taj Mahal until mid-morning.
If you want good weather and breathable air at the same time, the honest windows are shorter: late September to October, before the burning season starts, and February to mid-March, after the winter inversion breaks. We would rather tell you that than sell you a November trip and let you find out.
Month by month
| Months | Weather | Air quality | Verdict |
|---|---|---|---|
| Oct | Warm days, cool evenings, 30–20°C | Good early, worsening late in the month | One of the two best windows — go early in October |
| Nov | Pleasant, 27–12°C | Worst of the year — stubble burning plus Diwali | Lovely weather, genuinely bad air |
| Dec–Jan | Cold, 20–6°C, damp mornings | Poor to severe, plus heavy fog | Fog delays flights and hides the Taj until mid-morning |
| Feb–mid Mar | Warming, 25–12°C, clear | Improving steadily | The other best window — clean-ish air, comfortable days |
| Late Mar–Apr | Hot, 35°C and climbing | Moderate | Still workable if you start early |
| May–Jun | Very hot, 40–45°C+ | Moderate, dusty | Sightseeing has to be built around dawn |
| Jul–Sep | Monsoon, humid, 35–27°C | Best of the year — rain clears the air | Green, cheap, quiet; rain interrupts rather than prevents |
The pollution season, explained honestly
Delhi's winter air is a real problem and not one a travel company should talk around. From late October through January the AQI regularly runs in the very unhealthy to hazardous range, and on the worst days visibility drops to a few hundred metres.
Three things stack up at once. Farmers in Punjab and Haryana burn crop stubble in late October and November. Diwali fireworks land in the same window. And a winter temperature inversion traps all of it over the city instead of letting it disperse — which is why the same emissions produce far worse air in December than in July.
For most healthy adults a week in it is unpleasant rather than dangerous — expect a scratchy throat and tired eyes. If you have asthma or another respiratory condition, are travelling with young children, or are pregnant, November to January is worth avoiding, and we will say so if you ask us about those dates.
- Check a live AQI reading for your dates rather than an annual average — the day-to-day swing is enormous.
- An N95 or FFP2 mask genuinely helps on bad days. A surgical mask does not.
- Indoor time in the middle of the day helps; the museums and Akshardham are good bad-air options.
- Air purifiers are standard in better Delhi hotels in winter — worth asking before booking.
Winter fog and what it does to your plans
December and January fog in the Delhi–Agra corridor is dense enough to delay flights and trains regularly, and to hide the Taj Mahal completely until nine or ten in the morning. It is not a light mist; on the worst mornings the monument is invisible from inside the complex.
If a winter sunrise at the Taj is the point of your trip, build in a second morning. That is the whole argument for the overnight Agra tour over a day trip in those months — you have another attempt rather than a wasted drive.
Flight delays compound the same problem. Book domestic connections with real buffers in December and January, and avoid same-day international connections out of Delhi if you can.
The two windows worth aiming for
Late September to the middle of October is the first. The monsoon has cleared the air, the heat has broken, and the stubble burning has not started. The city is green in a way most visitors never see it, and hotel rates have not reached peak season.
February to the middle of March is the second, and for most trips it is the better one. The inversion has broken so the air is improving week by week, the days sit around a comfortable 25°C, the fog risk is gone, and Holi usually falls in this window if that interests you.
Both avoid the two things that spoil a Delhi trip — the heat of May and June and the air of November to January. If your dates are fixed and they fall in the bad window, the trip still works; it just needs planning around indoor time and early starts.
If your dates are fixed
- Travelling in November to January — go early in the morning when the air is marginally better, keep midday for museums and Akshardham, and bring an N95.
- Travelling in May or June — everything happens before 10am or after 5pm. The sunrise Taj Mahal tour gets punishing in June; the overnight version is the sensible swap.
- Travelling in the monsoon — the air is the best of the year and the crowds the thinnest. Rain comes in bursts rather than all day, and it rarely cancels anything outright.
- Travelling around Diwali — the city is beautifully lit and the air is at its worst. Both are true at once, and which matters more is your call rather than ours.
Common questions
What is the best month to visit Delhi?
February, or early October. Both give you comfortable days without the two things that spoil a Delhi trip — the 45°C heat of May and June, and the hazardous air of November to January. February has the edge: the winter inversion has broken so the air is improving, the fog risk has gone, and days sit around a pleasant 25°C.
How bad is Delhi pollution for tourists?
From late October to January it is genuinely bad — the AQI regularly reaches the very unhealthy to hazardous range. For a healthy adult, a week in it usually means a scratchy throat and tired eyes rather than anything worse. If you have asthma or another respiratory condition, are pregnant, or are travelling with young children, those months are worth avoiding. The rest of the year is far better, and monsoon air is the cleanest of all.
Why is Delhi air so bad in winter?
Three things coincide. Crop stubble burning in Punjab and Haryana peaks in late October and November, Diwali fireworks fall in the same weeks, and a winter temperature inversion traps the result over the city rather than letting it disperse. The same emissions in July produce far better air, because the monsoon washes them out and nothing holds them down.
Should I avoid Delhi in the monsoon?
No — it is underrated. July to September has the cleanest air of the year, the thinnest crowds and the lowest prices, and the city is green in a way winter visitors never see. Rain tends to come in heavy bursts rather than all day, so it interrupts a plan rather than cancelling it. Humidity is the real cost, and some Old Delhi lanes flood.
Will fog ruin a winter Taj Mahal trip?
It can. December and January fog in the Delhi–Agra corridor can hide the monument until nine or ten in the morning and delays flights and trains regularly. Nobody can forecast it more than a day or two ahead. If a winter sunrise matters to you, stay overnight in Agra so you have a second morning in reserve rather than one attempt after a three-hour drive.
When is Delhi least crowded?
July to September, during the monsoon, when both foreign and domestic tourism drop off. May and June are also quiet because of the heat. Peak season runs October to March, and the busiest single stretch is late December into early January, when hotel rates are at their highest and the monuments are fullest.