Weather in San Isidro in July
Costa Rica · 20-year averages, July
Shoulder season. July is shoulder season in San Isidro — cheaper, quieter, and a genuine gamble. You should expect rain on 26 days of the month, which is more days wet than dry.
July ranks 8 of 12 in San Isidro: past the worst of the year but short of February, which is the month to book if the dates are open.
Rain on 26 of the month's 31 days, 9 of them heavy. At that frequency a wet-weather backup is not a contingency, it is the itinerary — book the indoor things first and treat the clear days as the bonus. Natural fibres and a second shirt for the day. At 88% nothing dries, including you.
What the averages hide
Averages flatten a month, and this one hides a few things: it never really gets hot: not one day in an average July reaches 30 °C; the day barely swings — 5.1 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest July day reached 29 °C and the coldest night fell to 18.2 °C, and the wettest single day dropped 88 mm — roughly 33% of the month's rain in one day.
July is moderately variable: 112 mm in the driest year against 646 mm in the wettest, around an average of 266 mm. Roughly two Julys in three land near that average, and the third does something else entirely.
Wind is light at 1.5 km/h, so the temperature on the page is close to the temperature on your skin, and humidity at 88% is the real story though — it is the number that decides how the day feels, not the 26.4 °C.
How July sits in the year
Temperatures hold steady either side: 26.6 °C in June, 26.4 here, 26.5 in August. Nothing about the timing within the month matters much.
Daylight in July
San Isidro sits close enough to the equator that daylight barely moves all year — 12.6 hours in July, against a range of just 1.1 hours across the whole calendar. Sunrise and sunset land at roughly the same time whenever you come.
An inland climate
Despite being inland, the year stays fairly even: 9.3 °C between the year's warmest afternoons and coldest nights. At 713 m the air is thin enough to matter — sun that burns faster than the temperature suggests, and nights that cool off quickly.
How busy it gets
Quiet. Few other visitors, cheaper rooms, and a real chance some seasonal operators are shut.
Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.
July in San Isidro versus nearby
If San Isidro is one option among several, the nearby comparison is worth making. San José is close enough to be a coin toss — 2.5 °C cooler, 2 days less rain. Limón is close enough to be a coin toss — 2.1 °C warmer, 3 days more rain.
So: July works, with February the better month by 18 points if the dates can move. If they cannot, nothing here should stop you booking.
Every month in San Isidro
| Month | High °C | Low °C | Rain days | Rain mm | Humidity % | Daylight h | Score |
|---|---|---|---|---|---|---|---|
| January | 26.4 | 20.1 | 13 | 101 | 81 | 11.6 | 74 |
| February | 27.8 | 19.9 | 12 | 60 | 77 | 11.8 | 76 |
| March | 29.2 | 20.3 | 14 | 72 | 74 | 12.1 | 66 |
| April | 29.2 | 21.1 | 17 | 125 | 78 | 12.3 | 59 |
| May | 27.5 | 21.7 | 26 | 253 | 87 | 12.5 | 56 |
| June | 26.6 | 21.6 | 26 | 240 | 89 | 12.7 | 57 |
| July | 26.4 | 21.3 | 26 | 266 | 88 | 12.6 | 58 |
| August | 26.5 | 21.3 | 26 | 226 | 88 | 12.4 | 58 |
| September | 26.4 | 21.1 | 26 | 233 | 90 | 12.2 | 56 |
| October | 25.6 | 21.1 | 27 | 277 | 92 | 11.9 | 65 |
| November | 25.7 | 20.8 | 25 | 254 | 90 | 11.7 | 65 |
| December | 26.1 | 20.5 | 19 | 150 | 85 | 11.6 | 61 |
See all twelve months in San Isidro, or where else to go in July.
Planning the rest of the trip
- Flight time to San Isidro how long you are actually in the air
- San Isidro time zone and the difference from home
- Days until your trip count down to the departure date