Click on a day for an hourly weather forecast
The temperatures in Alajuela in September are comfortable with low of 19°C and and high up to 26°C.
With more than 22 rainy days, Alajuela is an incredibly wet during September. Be sure to pack your umbrella and bring along your rubber boots to stay dry. It’s going to be raining cats and dogs this month!
Our weather forecast can give you a great sense of what weather to expect in Alajuela in September 2025.
If you’re planning to visit Alajuela in the near future, we highly recommend that you review the 14 day weather forecast for Alajuela before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 28° / 17° | 2 | 29 | 0 | 42 mm | Perfect | Alajuela in January |
| February | 29° / 17° | 2 | 26 | 0 | 41 mm | Good | Alajuela in February |
| March | 30° / 18° | 3 | 28 | 0 | 50 mm | Good | Alajuela in March |
| April | 30° / 19° | 12 | 18 | 0 | 186 mm | Ok | Alajuela in April |
| May | 27° / 20° | 23 | 8 | 0 | 640 mm | Good | Alajuela in May |
| June | 26° / 20° | 25 | 5 | 0 | 741 mm | Good | Alajuela in June |
| July | 26° / 19° | 23 | 8 | 0 | 585 mm | Good | Alajuela in July |
| August | 26° / 19° | 23 | 8 | 0 | 629 mm | Good | Alajuela in August |
| September | 26° / 19° | 28 | 2 | 0 | 708 mm | Awful | Alajuela in September |
| October | 26° / 19° | 27 | 4 | 0 | 819 mm | Awful | Alajuela in October |
| November | 26° / 18° | 19 | 11 | 0 | 368 mm | Good | Alajuela in November |
| December | 27° / 17° | 6 | 25 | 0 | 114 mm | Perfect | Alajuela in December |