Piauí weather in September
September is a fair month to visit Piauí: highs of 37°C (99°F) and about 7 mm (0.3 in) of rain on average. Nights average 24°C (76°F) and cloud cover 30% (NASA POWER, 2001–2025 averages). It is the driest month of the year and the 2nd warmest. Compared with August, it is warmer and about as wet; October brings highs of 38°C (100°F) and 21 mm (0.8 in) of rain.
Figures are long-term averages for Teresina, the largest city in Piauí. See below for other places.
Is September a good time to visit Piauí?
fair month Weather score 68/100.
September is a fair month in Piauí. The weather is usually best in Jun–Aug.
Does it rain a lot in Piauí in September?
No, it is usually dry: about 7 mm (0.3 in) falls in an average September. It is the driest month of the year.
How warm is Piauí in September?
Days average 37°C (99°F) and nights 24°C (76°F).
Piauí weather by month
| Month | High | Low | Rain | Cloud | Weather |
|---|---|---|---|---|---|
| January | 32°C (89°F) | 23°C (74°F) | 184 mm | 74% | least pleasant |
| February | 30°C (86°F) | 23°C (73°F) | 227 mm | 78% | least pleasant |
| March | 30°C (85°F) | 23°C (73°F) | 261 mm | 77% | least pleasant |
| April | 29°C (85°F) | 23°C (73°F) | 239 mm | 73% | least pleasant |
| May | 30°C (87°F) | 22°C (72°F) | 106 mm | 53% | fair |
| June | 32°C (89°F) | 22°C (72°F) | 24 mm | 37% | best |
| July | 33°C (92°F) | 22°C (72°F) | 11 mm | 29% | best |
| August | 35°C (96°F) | 23°C (74°F) | 7 mm | 24% | best |
| September | 37°C (99°F) | 24°C (76°F) | 7 mm | 30% | fair |
| October | 38°C (100°F) | 25°C (77°F) | 21 mm | 43% | fair |
| November | 37°C (98°F) | 25°C (77°F) | 39 mm | 53% | fair |
| December | 35°C (95°F) | 24°C (76°F) | 77 mm | 63% | fair |
Sources: 2001–2025 monthly averages from NASA POWER (MERRA-2 reanalysis). Page updated . How we rate months
Weather across Piauí in September
Weather can differ a lot within Piauí: coasts, hills and mountains each have their own climate.
| Place | High | Low | Rain | Weather |
|---|---|---|---|---|
| Teresina | 37°C (99°F) | 24°C (76°F) | 7 mm | fair |
| Parnaíba | 35°C (96°F) | 23°C (73°F) | 4 mm | best |
| Picos | 37°C (98°F) | 22°C (71°F) | 5 mm | fair |
| Piripiri | 38°C (100°F) | 23°C (73°F) | 6 mm | fair |
| Floriano | 38°C (100°F) | 24°C (75°F) | 8 mm | fair |
| Barras | 36°C (97°F) | 23°C (74°F) | 10 mm | best |
| Altos | 37°C (99°F) | 24°C (76°F) | 7 mm | fair |
| Campo Maior | 38°C (100°F) | 24°C (75°F) | 4 mm | fair |
| União | 36°C (97°F) | 24°C (75°F) | 9 mm | fair |
| Esperantina | 36°C (97°F) | 23°C (74°F) | 10 mm | best |
| José de Freitas | 37°C (99°F) | 24°C (76°F) | 7 mm | fair |
| São Raimundo Nonato | 36°C (96°F) | 21°C (69°F) | 3 mm | fair |