Every hour we check our own rain forecast against government rain gauges and IMD radar, and show the result here.
Tuesday, 27 Oct
We said rain: none
Rain fell: none
Monday, 26 Oct
We said rain: none
Rain fell: none
Sunday, 25 Oct
We said rain: 12 AM – 2 AM, 5 AM – 8 AM, 12 PM – 8 PM, 10 PM
Rain fell: 12 AM, 12 PM – 2 PM, 6 PM, 11 PM
Every morning it checks what 9 weather models forecast the day before against the government rain gauges in all 38 districts, and retrains its own chance-of-rain model (machine learning).
Learned so far from 950 district-days over 25 days. The model it trusts most right now: ECMWF AI.
In a test on October 2026 (each day predicted only from the days before): rain or dry right on 75% of days, up from 69%. Rain amounts and heavy-rain warnings still come from the best models' middle forecast.
| District | Said rain, came | Rain, warned |
|---|---|---|
| Theni | 100% (51) | 94% (72) |
| Sivaganga | 96% (45) | 86% (64) |
| Mayiladuthurai | 65% (43) | 89% (28) |
| Tiruvarur | 41% (41) | 80% (15) |
| Cuddalore | 59% (37) | 88% (17) |
| Thoothukudi | 65% (23) | 68% (31) |
| Nagapattinam | 45% (38) | 93% (15) |
| Ariyalur | 71% (28) | 83% (24) |
At each district headquarters, for the forecast made an hour ahead, counted as right within an hour either side. Rain = 0.5 mm or more in an hour at an automatic government gauge within 10 km, or rain on the radar. Numbers in brackets are hours.
| 50% (30) |
| 67% (21) |
| Tirunelveli | 52% (33) | 75% (16) |
| Virudhunagar | 53% (30) | 89% (19) |
| Tiruchirappalli | 71% (31) | 100% (16) |
| Viluppuram | 62% (29) | 83% (18) |
| The Nilgiris | 71% (21) | 52% (25) |
| Kallakurichi | 64% (28) | 94% (17) |
| Thanjavur | 69% (29) | 88% (16) |
| Kanyakumari | 75% (20) | 54% (24) |
| Perambalur | 64% (25) | 89% (18) |
| Salem | 45% (31) | 83% (12) |
| Ramanathapuram | 14% (36) | 100% (6) |
| Namakkal | 64% (28) | 100% (13) |
| Dindigul | 60% (25) | 73% (15) |
| Tenkasi | 60% (25) | 86% (14) |
| Erode | 27% (33) | 100% (4) |
| Dharmapuri | 39% (23) | 54% (13) |
| Pudukkottai | 52% (27) | 100% (8) |
| Karur | 0% (34) | – (0) |
| Tiruppur | 38% (24) | 70% (10) |
| Tiruvannamalai | 52% (23) | 82% (11) |
| Kanchipuram | 55% (20) | 85% (13) |
| Ranipet | 68% (19) | 77% (13) |
| Krishnagiri | 35% (20) | 64% (11) |
| Vellore | 53% (17) | 64% (14) |
| Chengalpattu | 42% (19) | 70% (10) |
| Coimbatore | 53% (15) | 50% (12) |
| Tirupathur | 13% (15) | 18% (11) |
| Tiruvallur | 45% (11) | 50% (10) |
| Chennai | 24% (17) | 100% (3) |