San Juan weather in March
In March, San Juan sees average daytime highs of 28°C and overnight lows near 23°C, with 39 mm of rain across 8.4 wet days and about 11.9 hours of daylight. It is the 9th-warmest and 10th-wettest month of the year here.
Day-to-day highs hold fairly steady near 28°C through the month. The sky is clear or mostly clear about 54% of the time in March, and the air most often feels muggy.
Daylight stretches from about 11 h 36 min at the start of March to 12 h 06 min by month's end. Set against the rest of the year, March is San Juan's 4th-clearest and 6th-windiest month. For the whole year in context, see San Juan's year-round climate.
- Daytime high
- 28°
- 9th warmest
- Overnight low
- 23°
- 3rd coldest
- Rainfall
- 39 mm
- 8.4 wet days
- Daylight
- 11 h 54 min
- 6:38 AM – 6:30 PM
- Cloud cover
- 42%
- 4th clearest
- Wind
- 15 km/h
- 6th windiest
- Solar energy
- 6.04 kWh/m²
- Travel score
- 6.9
- out of 10
San Juan is capital of Puerto Rico.
- Density
- 3,479/km²
- people per km²
- Founded
- 1521
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in March
Day-to-day highs hold fairly steady near 28°C through the month.
A typical March day in San Juan reaches about 28°C in the afternoon and slips back to 23°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 29°C. Set against its neighbours, March runs on par with February and on par with April.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 27 | 27 | 27 | 27 | 27 | 27 | 27 | 27 | 27 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 |
| Avg low (°C) | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| 1 | 27 | 22 |
| 2 | 27 | 22 |
| 3 | 27 | 22 |
| 4 | 27 | 22 |
| 5 | 27 | 22 |
| 6 | 27 | 22 |
| 7 | 27 | 22 |
| 8 | 27 | 22 |
| 9 | 27 | 22 |
| 10 | 28 | 22 |
| 11 | 28 | 22 |
| 12 | 28 | 22 |
| 13 | 28 | 22 |
| 14 | 28 | 22 |
| 15 | 28 | 22 |
| 16 | 28 | 22 |
| 17 | 28 | 22 |
| 18 | 28 | 23 |
| 19 | 28 | 23 |
| 20 | 28 | 23 |
| 21 | 28 | 23 |
| 22 | 28 | 23 |
| 23 | 28 | 23 |
| 24 | 28 | 23 |
| 25 | 28 | 23 |
| 26 | 28 | 23 |
| 27 | 28 | 23 |
| 28 | 28 | 23 |
| 29 | 28 | 23 |
| 30 | 28 | 23 |
| 31 | 28 | 23 |
How March really feels in San Juan
Once humidity and wind are folded in, March averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.
March sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
San Juan weather by month
How March compares with the rest of the year at a glance. March is the 9th-warmest and 10th-wettest month here — the current month is highlighted below.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 27° / 23° | 39 | 10.4 | 11 | 6.8 |
| Feb | 27° / 22° | 28 | 7.6 | 11.4 | 7.1 |
| Mar | 28° / 23° | 39 | 8.4 | 11.9 | 6.9 |
| Apr | 28° / 23° | 72 | 11 | 12.4 | 5.8 |
| May | 29° / 24° | 112 | 16.2 | 12.9 | 4.7 |
| Jun | 30° / 25° | 68 | 13.9 | 13.1 | 4.5 |
| Jul | 30° / 25° | 80 | 16.5 | 13 | 4.4 |
| Aug | 30° / 25° | 95 | 18.7 | 12.6 | 4.0 |
| Sep | 30° / 25° | 131 | 20.8 | 12.1 | 3.7 |
| Oct | 29° / 25° | 125 | 20.5 | 11.6 | 4.0 |
| Nov | 28° / 24° | 112 | 18.2 | 11.1 | 4.9 |
| Dec | 27° / 23° | 48 | 12.2 | 10.9 | 6.4 |
Cloud cover in March
The sky is clear or mostly clear about 54% of the time in March.
Beyond those clear spells, partly cloudy skies cover about 27% of March, with mostly cloudy or overcast conditions the remaining 19%. Skies tend to cloud over as the month goes on.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 83 | 82 | 82 | 82 | 81 | 81 | 80 | 80 | 80 | 81 | 81 | 81 | 82 | 82 | 83 | 83 | 83 | 83 | 83 | 83 | 82 | 82 | 82 | 81 | 81 | 81 | 79 | 79 | 79 | 78 | 77 |
| Cloudier (%) | 17 | 18 | 18 | 18 | 19 | 19 | 20 | 20 | 20 | 19 | 19 | 19 | 18 | 18 | 17 | 17 | 17 | 17 | 17 | 17 | 18 | 18 | 18 | 19 | 19 | 19 | 21 | 21 | 21 | 22 | 23 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 83 | 17 |
| 2 | 82 | 18 |
| 3 | 82 | 18 |
| 4 | 82 | 18 |
| 5 | 81 | 19 |
| 6 | 81 | 19 |
| 7 | 80 | 20 |
| 8 | 80 | 20 |
| 9 | 80 | 20 |
| 10 | 81 | 19 |
| 11 | 81 | 19 |
| 12 | 81 | 19 |
| 13 | 82 | 18 |
| 14 | 82 | 18 |
| 15 | 83 | 17 |
| 16 | 83 | 17 |
| 17 | 83 | 17 |
| 18 | 83 | 17 |
| 19 | 83 | 17 |
| 20 | 83 | 17 |
| 21 | 82 | 18 |
| 22 | 82 | 18 |
| 23 | 82 | 18 |
| 24 | 81 | 19 |
| 25 | 81 | 19 |
| 26 | 81 | 19 |
| 27 | 79 | 21 |
| 28 | 79 | 21 |
| 29 | 79 | 21 |
| 30 | 78 | 22 |
| 31 | 77 | 23 |
Chance of precipitation in March
San Juan gets around 39 mm of rain over 8.4 wet days in March. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 27% and peaks near 33% on the wettest days. The odds climb toward the end of the month.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 26 | 26 | 26 | 25 | 25 | 25 | 24 | 24 | 24 | 24 | 24 | 24 | 24 | 24 | 24 | 24 | 25 | 25 | 26 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 32 | 33 | 33 | 33 | 33 |
| Rain chance (%) | |
|---|---|
| 1 | 26 |
| 2 | 26 |
| 3 | 26 |
| 4 | 25 |
| 5 | 25 |
| 6 | 25 |
| 7 | 24 |
| 8 | 24 |
| 9 | 24 |
| 10 | 24 |
| 11 | 24 |
| 12 | 24 |
| 13 | 24 |
| 14 | 24 |
| 15 | 24 |
| 16 | 24 |
| 17 | 25 |
| 18 | 25 |
| 19 | 26 |
| 20 | 26 |
| 21 | 27 |
| 22 | 28 |
| 23 | 29 |
| 24 | 30 |
| 25 | 31 |
| 26 | 32 |
| 27 | 32 |
| 28 | 33 |
| 29 | 33 |
| 30 | 33 |
| 31 | 33 |
Humidity in March
Most of March feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, March lands in the muggy band about 67% of days. Sticky, muggy-or-worse air turns up on roughly 87% of them.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Comfortable (%) | 1 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Humid (%) | 13 | 13 | 14 | 14 | 15 | 15 | 15 | 15 | 15 | 15 | 14 | 14 | 14 | 13 | 13 | 12 | 12 | 11 | 11 | 10 | 9 | 9 | 9 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 |
| Muggy (%) | 72 | 71 | 70 | 70 | 69 | 69 | 69 | 69 | 69 | 69 | 70 | 69 | 69 | 70 | 70 | 70 | 69 | 69 | 68 | 68 | 68 | 67 | 65 | 66 | 65 | 64 | 63 | 61 | 60 | 59 | 58 |
| Oppressive (%) | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 15 | 15 | 16 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 25 | 26 | 27 | 28 | 29 | 31 | 32 | 33 | 34 |
| Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | |
|---|---|---|---|---|
| 1 | 1 | 13 | 72 | 14 |
| 2 | 2 | 13 | 71 | 14 |
| 3 | 2 | 14 | 70 | 14 |
| 4 | 2 | 14 | 70 | 14 |
| 5 | 2 | 15 | 69 | 14 |
| 6 | 2 | 15 | 69 | 14 |
| 7 | 2 | 15 | 69 | 14 |
| 8 | 2 | 15 | 69 | 14 |
| 9 | 2 | 15 | 69 | 14 |
| 10 | 2 | 15 | 69 | 14 |
| 11 | 2 | 14 | 70 | 14 |
| 12 | 2 | 14 | 69 | 15 |
| 13 | 2 | 14 | 69 | 15 |
| 14 | 1 | 13 | 70 | 16 |
| 15 | 1 | 13 | 70 | 16 |
| 16 | 1 | 12 | 70 | 17 |
| 17 | 1 | 12 | 69 | 18 |
| 18 | 1 | 11 | 69 | 19 |
| 19 | 1 | 11 | 68 | 20 |
| 20 | 1 | 10 | 68 | 21 |
| 21 | 1 | 9 | 68 | 22 |
| 22 | 1 | 9 | 67 | 23 |
| 23 | 1 | 9 | 65 | 25 |
| 24 | 0 | 8 | 66 | 26 |
| 25 | 0 | 8 | 65 | 27 |
| 26 | 0 | 8 | 64 | 28 |
| 27 | 0 | 8 | 63 | 29 |
| 28 | 0 | 8 | 61 | 31 |
| 29 | 0 | 8 | 60 | 32 |
| 30 | 0 | 8 | 59 | 33 |
| 31 | 0 | 8 | 58 | 34 |
Wind in March
Winds average 15 km/h in March.
Across March, daily wind ranges from about 14 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 |
| Feels | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze |
| Wind speed (km/h) | Feels | |
|---|---|---|
| 1 | 15 | light breeze |
| 2 | 15 | light breeze |
| 3 | 15 | light breeze |
| 4 | 15 | light breeze |
| 5 | 15 | light breeze |
| 6 | 15 | light breeze |
| 7 | 15 | light breeze |
| 8 | 15 | light breeze |
| 9 | 15 | light breeze |
| 10 | 15 | light breeze |
| 11 | 15 | light breeze |
| 12 | 15 | light breeze |
| 13 | 15 | light breeze |
| 14 | 15 | light breeze |
| 15 | 15 | light breeze |
| 16 | 15 | light breeze |
| 17 | 14 | light breeze |
| 18 | 14 | light breeze |
| 19 | 14 | light breeze |
| 20 | 14 | light breeze |
| 21 | 14 | light breeze |
| 22 | 14 | light breeze |
| 23 | 14 | light breeze |
| 24 | 14 | light breeze |
| 25 | 14 | light breeze |
| 26 | 14 | light breeze |
| 27 | 14 | light breeze |
| 28 | 14 | light breeze |
| 29 | 14 | light breeze |
| 30 | 14 | light breeze |
| 31 | 14 | light breeze |
Sunrise & sunset in March
Daylight runs from about 11 h 36 min at the start of March to 12 h 06 min by month's end. The lit band spans sunrise to sunset each day.
Days grow by about 30 minutes over March. Sunrise moves from 6:49 AM to 6:25 AM, and sunset from 6:26 PM to 6:34 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 11.6 | 11.6 | 11.6 | 11.7 | 11.7 | 11.7 | 11.7 | 11.7 | 11.7 | 11.8 | 11.8 | 11.8 | 11.8 | 11.8 | 11.9 | 11.9 | 11.9 | 11.9 | 11.9 | 11.9 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.1 | 12.1 | 12.1 | 12.1 | 12.1 |
| Sunrise (AM) | 6:49 | 6:49 | 6:48 | 6:47 | 6:47 | 6:46 | 6:45 | 6:44 | 6:44 | 6:43 | 6:42 | 6:41 | 6:40 | 6:40 | 6:39 | 6:38 | 6:37 | 6:36 | 6:35 | 6:35 | 6:34 | 6:33 | 6:32 | 6:31 | 6:30 | 6:30 | 6:29 | 6:28 | 6:27 | 6:26 | 6:25 |
| Sunset (PM) | 6:26 | 6:26 | 6:27 | 6:27 | 6:27 | 6:27 | 6:28 | 6:28 | 6:28 | 6:29 | 6:29 | 6:29 | 6:29 | 6:30 | 6:30 | 6:30 | 6:30 | 6:31 | 6:31 | 6:31 | 6:31 | 6:32 | 6:32 | 6:32 | 6:32 | 6:32 | 6:33 | 6:33 | 6:33 | 6:33 | 6:34 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 11.6 | 6:49 | 6:26 |
| 2 | 11.6 | 6:49 | 6:26 |
| 3 | 11.6 | 6:48 | 6:27 |
| 4 | 11.7 | 6:47 | 6:27 |
| 5 | 11.7 | 6:47 | 6:27 |
| 6 | 11.7 | 6:46 | 6:27 |
| 7 | 11.7 | 6:45 | 6:28 |
| 8 | 11.7 | 6:44 | 6:28 |
| 9 | 11.7 | 6:44 | 6:28 |
| 10 | 11.8 | 6:43 | 6:29 |
| 11 | 11.8 | 6:42 | 6:29 |
| 12 | 11.8 | 6:41 | 6:29 |
| 13 | 11.8 | 6:40 | 6:29 |
| 14 | 11.8 | 6:40 | 6:30 |
| 15 | 11.9 | 6:39 | 6:30 |
| 16 | 11.9 | 6:38 | 6:30 |
| 17 | 11.9 | 6:37 | 6:30 |
| 18 | 11.9 | 6:36 | 6:31 |
| 19 | 11.9 | 6:35 | 6:31 |
| 20 | 11.9 | 6:35 | 6:31 |
| 21 | 12.0 | 6:34 | 6:31 |
| 22 | 12.0 | 6:33 | 6:32 |
| 23 | 12.0 | 6:32 | 6:32 |
| 24 | 12.0 | 6:31 | 6:32 |
| 25 | 12.0 | 6:30 | 6:32 |
| 26 | 12.0 | 6:30 | 6:32 |
| 27 | 12.1 | 6:29 | 6:33 |
| 28 | 12.1 | 6:28 | 6:33 |
| 29 | 12.1 | 6:27 | 6:33 |
| 30 | 12.1 | 6:26 | 6:33 |
| 31 | 12.1 | 6:25 | 6:34 |
Solar energy in March
Average shortwave solar energy reaching the ground each day in March, about 6.04 kWh/m².
For context, solar energy here swings from a low near 4.34 kWh/m² to a high of 6.56 kWh/m² in June across the year — March's 6.04 kWh/m² falls in the middle.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 5.7 | 5.7 | 5.7 | 5.7 | 5.8 | 5.8 | 5.8 | 5.8 | 5.9 | 5.9 | 5.9 | 6.0 | 6.0 | 6.0 | 6.0 | 6.1 | 6.1 | 6.1 | 6.1 | 6.2 | 6.2 | 6.2 | 6.2 | 6.2 | 6.3 | 6.3 | 6.3 | 6.3 | 6.3 | 6.3 | 6.4 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 5.7 | Bright |
| 2 | 5.7 | Bright |
| 3 | 5.7 | Bright |
| 4 | 5.7 | Bright |
| 5 | 5.8 | Bright |
| 6 | 5.8 | Bright |
| 7 | 5.8 | Bright |
| 8 | 5.8 | Bright |
| 9 | 5.9 | Bright |
| 10 | 5.9 | Bright |
| 11 | 5.9 | Bright |
| 12 | 6.0 | Bright |
| 13 | 6.0 | Bright |
| 14 | 6.0 | Intense |
| 15 | 6.0 | Intense |
| 16 | 6.1 | Intense |
| 17 | 6.1 | Intense |
| 18 | 6.1 | Intense |
| 19 | 6.1 | Intense |
| 20 | 6.2 | Intense |
| 21 | 6.2 | Intense |
| 22 | 6.2 | Intense |
| 23 | 6.2 | Intense |
| 24 | 6.2 | Intense |
| 25 | 6.3 | Intense |
| 26 | 6.3 | Intense |
| 27 | 6.3 | Intense |
| 28 | 6.3 | Intense |
| 29 | 6.3 | Intense |
| 30 | 6.3 | Intense |
| 31 | 6.4 | Intense |
Hazard calendar for San Juan
None of San Juan's seasonal hazards are active in March. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.
San Juan sits in the Atlantic hurricane belt; the season peaks August–October.
San Juan sees seasonal dust haze (July), heaviest in July.
Is March a good time to visit San Juan?
Our two travel scores rate March for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
March is a reasonable time to visit San Juan for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for San Juan in March
From March's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In March, San Juan sees daytime highs around 28°C and nights near 23°C. Pack light clothes and sun protection. Worth having: rain gear. About 8 days see rain.
Sea temperature near San Juan in March
The nearest coast averages about 26°C in March — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 18 km away) is warmest in September at about 29°C and coldest in February near 26°C.
The water stays above 20°C all year — warm enough for a swim any month.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 27 | 26 | 26 | 27 | 27 | 28 | 28 | 29 | 29 | 29 | 28 | 27 |
| Comfort | Warm | Warm | Warm | Warm | Warm | Warm | Tropical | Tropical | Tropical | Tropical | Tropical | Warm |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 27 | Warm |
| Feb | 26 | Warm |
| Mar | 26 | Warm |
| Apr | 27 | Warm |
| May | 27 | Warm |
| Jun | 28 | Warm |
| Jul | 28 | Tropical |
| Aug | 29 | Tropical |
| Sep | 29 | Tropical |
| Oct | 29 | Tropical |
| Nov | 28 | Tropical |
| Dec | 27 | Warm |
UV index in San Juan in March
Clear-sky midday UV in March peaks around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in San Juan peaks around April 13 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 7 (high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 8 | 10 | 12 | 13 | 11 | 12 | 12 | 12 | 12 | 10 | 8 | 7 |
| Level | Very high | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Very high | Very high | High |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 8 | Very high |
| Feb | 10 | Extreme |
| Mar | 12 | Extreme |
| Apr | 13 | Extreme |
| May | 11 | Extreme |
| Jun | 12 | Extreme |
| Jul | 12 | Extreme |
| Aug | 12 | Extreme |
| Sep | 12 | Extreme |
| Oct | 10 | Very high |
| Nov | 8 | Very high |
| Dec | 7 | High |
Air quality in San Juan in March
Average fine-particle pollution (PM2.5) through the year — so you can see where March falls, not just the annual average.
Air quality in San Juan is worst in July — around 24 µg/m³ PM2.5 (moderate), about 4.6× the cleanest month (January, 5 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 5 | 7 | 7 | 8 | 14 | 23 | 24 | 20 | 15 | 15 | 8 | 5 |
| Level | Good | Good | Good | Good | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 5 | Good |
| Feb | 7 | Good |
| Mar | 7 | Good |
| Apr | 8 | Good |
| May | 14 | Moderate |
| Jun | 23 | Moderate |
| Jul | 24 | Moderate |
| Aug | 20 | Moderate |
| Sep | 15 | Moderate |
| Oct | 15 | Moderate |
| Nov | 8 | Good |
| Dec | 5 | Good |
Where is San Juan?
San Juan sits at 18.5°N, 66.1°W, 7 m above sea level, in Puerto Rico. The nearest listed city is Cataño, 3.0 km away.
Topography around San Juan
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Juan.
Within 3 km, the terrain around San Juan has only modest variations in elevation — a maximum elevation change of 42 m around an average of 2 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 289 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,308 m.
The land around San Juan is covered by water (81%) within 3 km, water (56%) and artificial surfaces (24%) within 16 km, and water (58%) and trees (32%) within 80 km.
Puerto Rico travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 78% of US
- price level, 2025
- GDP per capita
- $40,620
- 2025
- Happiness
- 7.0 / 10
- World Happiness, 2015
- Safe drinking water
- 99%
- of population, 2024
- Homicide rate
- 14.6
- per 100k, 2023
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for San Juan (18.4663°, -66.1057°, elevation 7 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).