🔎 Weather for a date or period
Actual day-by-day weather for the selected period (ERA5). Up to 1 year.
📆 On this day before
Data for previous years is being prepared.
🏆 Hottest and coldest day in San Juan (over the full observation series)
+36°
Hottest day
September 7, 1951
+17°
Coldest day
March 12, 1951
🗓 Monthly climate in San Juan
| Month | Day | Night | Precip |
|---|---|---|---|
| January | +28° | +22° | 53 mm |
| February | +28° | +22° | 60 mm |
| March | +29° | +22° | 56 mm |
| April | +30° | +23° | 79 mm |
| May | +31° | +24° | 79 mm |
| June | +32° | +25° | 61 mm |
| July | +31° | +25° | 80 mm |
| August | +31° | +25° | 92 mm |
| September | +31° | +25° | 155 mm |
| October | +31° | +24° | 125 mm |
| November | +29° | +24° | 133 mm |
| December | +28° | +23° | 62 mm |
🕰 Weather in San Juan August 18 in past years
+34°
Heat record · 1968
+23°
Cold record · 1984
📜
This day in history. The hottest August 18 in San Juan was in 1968 (+34°), the coldest in 1984 (+23°). 86 years of observations. Normal for August: day +31°, night +25°.
📒 For school and home
Weather diary
ready-made observation table for a month — for school
Weather for the month
August calendar: forecast + climate normal
City water
Caribbean Sea +29° — where to swim
FAQ about the weather archive in San Juan ❓
What was the weather in San Juan on a specific date?
Pick a date or range in the form above — we show actual day-by-day weather (ERA5 reanalysis, up to a year back). For today’s date in past years see “On this day before”.
Hottest and coldest day in the history in San Juan?
Heat record — +36° (September 7, 1951), cold record — +17° (March 12, 1951). Observations over the full available series.
What's the typical weather in San Juan in August?
On average +31° by day, +25° at night, precipitation about 92 mm (ERA5 climate normal).
Since what year is the weather archive in San Juan kept?
Climate normals and records come from the ERA5 reanalysis. Actual day-by-day weather is available for the last year.
Climate and weather archive in San Juan
Monthly climate normals in San Juan (average day and night temperatures, precipitation) are computed from the ERA5 reanalysis. The observation archive accrues from launch. Data: Open-Meteo (ERA5).