This guide describes Cuddalore's historical climate, not a live 15-day forecast. Monthly averages help compare seasons but cannot predict an individual day. Forecast uncertainty generally increases with lead time and depends on the location and weather variable. See the current seven-day forecast for upcoming weather.
What is normal in Cuddalore, month by month
| Month | Max | Min | Rain | Rain days |
|---|---|---|---|---|
| January | 27.3° | 22.2° | 27 mm | 5.4 |
| February | 28.7° | 22.6° | 12.3 mm | 2.9 |
| March | 30.7° | 24.1° | 18.6 mm | 2.8 |
| April | 32.4° | 26.6° | 26.9 mm | 4.9 |
| May | 33.9° | 27.9° | 47.5 mm | 6.3 |
| June | 33.9° | 27.7° | 47.8 mm | 9.7 |
| July | 33.3° | 27° | 60.4 mm | 12 |
| August | 32.6° | 26.6° | 92.6 mm | 14 |
| September | 32° | 26.3° | 97.1 mm | 15.2 |
| October | 30° | 25.1° | 224.9 mm | 20.3 |
| November | 27.9° | 23.9° | 313.6 mm | 20 |
| December | 27.1° | 22.9° | 155 mm | 12.3 |
Only 27% of Cuddalore's 1124 mm falls between June and September, against 62% between October and December, so it is in those last three months that a 15-day view is most useful for spotting when the next wet spell is due, not for how much rain falls on a given day.
How much a fortnight can tell you in Cuddalore
The wet season builds here rather than breaking. November carries about 3.2 times the rain of September - a real increase, but a gradual one - so a fortnight's view is genuinely about how much and when, not simply whether the season has started.
The other thing worth knowing before reading a two-week forecast here is how far the year swings: 11.7°C between the hottest monthly average maximum and the coldest average minimum. The fastest change is into November, when the average daily maximum moves 2.1°C in a single month - and a forecast crossing that point is doing more work than one in a settled month.
The biggest turn in the year
India Meteorological Department — Tamil Nadu has two monsoons, and here the second one matters more. During the southwest monsoon, June to September, the state lies in a rain shadow and receives only about 35% of its annual rainfall. Its chief rainy season is the northeast monsoon, October to December, which brings about 48%. IMD gives 20 October as the normal date for the northeast monsoon's onset over coastal Tamil Nadu. If you are looking at a 15-day outlook in mid-October, that is the real question you are asking.
We do not publish a calculated monsoon onset date for Cuddalore. Our method looks for the first sustained wet spell on or after 1 May, which across most of India is the southwest monsoon arriving. Here it is not: the southwest monsoon brings Cuddalore comparatively little rain, and the first spell to pass our test comes at very different points of the year from one year to the next — sometimes in May, sometimes not until October or later. A date that can land in any of those months is not the arrival of either monsoon, so we give IMD's figures instead.
The other turn is heat: May averages a daily maximum of 33.9°C, and that falls by 6°C once the monsoon is established.
When the monsoon reaches Cuddalore — the full record
Sources
Source: Open-Meteo's historical weather archive, whose default model blends ERA5 and ERA5-Land reanalysis with ECMWF IFS HRES from 2017 — 1991-2024 (34 years). Open-Meteo offers no rainfall from ERA5-Land, so the rain figures come from ERA5 and IFS. Temperatures are monthly averages of daily highs and lows; rainfall is the average monthly total. A grid estimate can differ from a local weather station.
The live forecast for Cuddalore is on a separate page and comes from Open-Meteo, which is built on ECMWF and other models.