Usulután weather in December
In December, Usulután sees average daytime highs of 31°C and overnight lows near 23°C, with 4 mm of rain across 1.2 wet days and about 11.2 hours of daylight. It is the 7th-warmest and 10th-wettest month of the year here.
Day-to-day highs hold fairly steady near 31°C through the month. The sky is clear or mostly clear about 80% of the time in December, and the air most often feels oppressive.
Daylight stretches from about 11 h 18 min at the start of December to 11 h 12 min by month's end. Set against the rest of the year, December is Usulután's 3rd-clearest and 5th-windiest month. For the whole year in context, see Usulután's year-round climate.
- Daytime high
- 31°
- 7th warmest
- Overnight low
- 23°
- 2nd coldest
- Rainfall
- 4 mm
- 1.2 wet days
- Daylight
- 11 h 12 min
- 6:13 AM – 5:26 PM
- Cloud cover
- 23%
- 3rd clearest
- Wind
- 7 km/h
- 5th windiest
- Solar energy
- 5.54 kWh/m²
- Travel score
- 5.7
- out of 10
Usulután is city in El Salvador.
- Density
- 371/km²
- people per km²
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in December
Day-to-day highs hold fairly steady near 31°C through the month.
A typical December day in Usulután reaches about 31°C in the afternoon and slips back to 23°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 30°C and 33°C. Set against its neighbours, December runs about 1°C warmer than November and on par with January.
| 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) | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 32 | 32 | 32 | 32 | 32 |
| Avg low (°C) | 24 | 24 | 24 | 24 | 24 | 24 | 24 | 24 | 24 | 24 | 24 | 24 | 24 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| 1 | 31 | 24 |
| 2 | 31 | 24 |
| 3 | 31 | 24 |
| 4 | 31 | 24 |
| 5 | 31 | 24 |
| 6 | 31 | 24 |
| 7 | 31 | 24 |
| 8 | 31 | 24 |
| 9 | 31 | 24 |
| 10 | 31 | 24 |
| 11 | 31 | 24 |
| 12 | 31 | 24 |
| 13 | 31 | 24 |
| 14 | 31 | 23 |
| 15 | 31 | 23 |
| 16 | 31 | 23 |
| 17 | 31 | 23 |
| 18 | 31 | 23 |
| 19 | 31 | 23 |
| 20 | 31 | 23 |
| 21 | 31 | 23 |
| 22 | 31 | 23 |
| 23 | 31 | 23 |
| 24 | 31 | 23 |
| 25 | 31 | 23 |
| 26 | 31 | 23 |
| 27 | 32 | 23 |
| 28 | 32 | 23 |
| 29 | 32 | 23 |
| 30 | 32 | 23 |
| 31 | 32 | 23 |
How December really feels in Usulután
Once humidity and wind are folded in, December averages 31 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.
The story in December is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Usulután weather by month
How December compares with the rest of the year at a glance. December is the 7th-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 | 32° / 23° | 1 | 0.3 | 11.3 | 5.6 |
| Feb | 32° / 24° | 2 | 0.4 | 11.6 | 5.3 |
| Mar | 32° / 24° | 7 | 1.8 | 11.9 | 4.9 |
| Apr | 32° / 25° | 29 | 8.1 | 12.3 | 4.1 |
| May | 31° / 25° | 220 | 22.3 | 12.6 | 3.1 |
| Jun | 31° / 25° | 288 | 23.9 | 12.8 | 3.0 |
| Jul | 31° / 25° | 198 | 19.4 | 12.7 | 3.4 |
| Aug | 31° / 25° | 273 | 23.3 | 12.4 | 3.2 |
| Sep | 30° / 25° | 342 | 26.6 | 12.1 | 3.0 |
| Oct | 30° / 24° | 349 | 24.6 | 11.7 | 3.5 |
| Nov | 30° / 24° | 71 | 9 | 11.4 | 5.1 |
| Dec | 31° / 23° | 4 | 1.2 | 11.2 | 5.7 |
Cloud cover in December
The sky is clear or mostly clear about 80% of the time in December.
Beyond those clear spells, partly cloudy skies cover about 9% of December, with mostly cloudy or overcast conditions the remaining 11%. Skies tend to open up 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 (%) | 80 | 81 | 82 | 84 | 84 | 85 | 86 | 87 | 87 | 88 | 89 | 89 | 90 | 90 | 90 | 91 | 91 | 91 | 92 | 92 | 93 | 93 | 93 | 93 | 93 | 93 | 92 | 92 | 92 | 92 | 91 |
| Cloudier (%) | 20 | 19 | 18 | 16 | 16 | 15 | 14 | 13 | 13 | 12 | 11 | 11 | 10 | 10 | 10 | 9 | 9 | 9 | 8 | 8 | 7 | 7 | 7 | 7 | 7 | 7 | 8 | 8 | 8 | 8 | 9 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 80 | 20 |
| 2 | 81 | 19 |
| 3 | 82 | 18 |
| 4 | 84 | 16 |
| 5 | 84 | 16 |
| 6 | 85 | 15 |
| 7 | 86 | 14 |
| 8 | 87 | 13 |
| 9 | 87 | 13 |
| 10 | 88 | 12 |
| 11 | 89 | 11 |
| 12 | 89 | 11 |
| 13 | 90 | 10 |
| 14 | 90 | 10 |
| 15 | 90 | 10 |
| 16 | 91 | 9 |
| 17 | 91 | 9 |
| 18 | 91 | 9 |
| 19 | 92 | 8 |
| 20 | 92 | 8 |
| 21 | 93 | 7 |
| 22 | 93 | 7 |
| 23 | 93 | 7 |
| 24 | 93 | 7 |
| 25 | 93 | 7 |
| 26 | 93 | 7 |
| 27 | 92 | 8 |
| 28 | 92 | 8 |
| 29 | 92 | 8 |
| 30 | 92 | 8 |
| 31 | 91 | 9 |
Chance of precipitation in December
Usulután gets around 4 mm of rain over 1.2 wet days in December. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 4% and peaks near 10% on the wettest days.
| 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 (%) | 10 | 9 | 8 | 7 | 6 | 5 | 5 | 4 | 4 | 4 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 3 | 3 | 3 |
| Rain chance (%) | |
|---|---|
| 1 | 10 |
| 2 | 9 |
| 3 | 8 |
| 4 | 7 |
| 5 | 6 |
| 6 | 5 |
| 7 | 5 |
| 8 | 4 |
| 9 | 4 |
| 10 | 4 |
| 11 | 3 |
| 12 | 3 |
| 13 | 3 |
| 14 | 3 |
| 15 | 3 |
| 16 | 3 |
| 17 | 3 |
| 18 | 3 |
| 19 | 3 |
| 20 | 3 |
| 21 | 3 |
| 22 | 4 |
| 23 | 4 |
| 24 | 4 |
| 25 | 4 |
| 26 | 4 |
| 27 | 4 |
| 28 | 4 |
| 29 | 3 |
| 30 | 3 |
| 31 | 3 |
Humidity in December
Most of December feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, December lands in the oppressive band about 43% of days. Sticky, muggy-or-worse air turns up on roughly 88% 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Comfortable (%) | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 4 |
| Humid (%) | 8 | 8 | 8 | 8 | 8 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 8 | 8 | 8 | 8 | 9 | 9 | 10 | 10 | 10 | 11 | 11 | 11 | 12 | 12 | 13 | 13 | 14 | 14 | 15 |
| Muggy (%) | 29 | 31 | 32 | 34 | 35 | 36 | 37 | 38 | 38 | 39 | 40 | 40 | 41 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 48 | 49 | 51 | 50 | 51 | 51 | 52 | 51 | 52 | 50 |
| Oppressive (%) | 55 | 54 | 54 | 52 | 52 | 52 | 52 | 50 | 51 | 49 | 49 | 48 | 47 | 47 | 46 | 45 | 43 | 42 | 41 | 40 | 39 | 37 | 36 | 35 | 35 | 34 | 33 | 32 | 32 | 31 | 31 |
| Miserable (%) | 8 | 7 | 6 | 5 | 4 | 4 | 3 | 3 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| 1 | 0 | 0 | 8 | 29 | 55 | 8 |
| 2 | 0 | 0 | 8 | 31 | 54 | 7 |
| 3 | 0 | 0 | 8 | 32 | 54 | 6 |
| 4 | 0 | 1 | 8 | 34 | 52 | 5 |
| 5 | 0 | 1 | 8 | 35 | 52 | 4 |
| 6 | 0 | 1 | 7 | 36 | 52 | 4 |
| 7 | 0 | 1 | 7 | 37 | 52 | 3 |
| 8 | 0 | 2 | 7 | 38 | 50 | 3 |
| 9 | 0 | 2 | 7 | 38 | 51 | 2 |
| 10 | 0 | 2 | 7 | 39 | 49 | 2 |
| 11 | 1 | 2 | 7 | 40 | 49 | 2 |
| 12 | 1 | 3 | 7 | 40 | 48 | 1 |
| 13 | 1 | 3 | 8 | 41 | 47 | 1 |
| 14 | 1 | 3 | 8 | 41 | 47 | 1 |
| 15 | 1 | 3 | 8 | 42 | 46 | 1 |
| 16 | 1 | 3 | 8 | 43 | 45 | 0 |
| 17 | 0 | 3 | 9 | 44 | 43 | 0 |
| 18 | 0 | 3 | 9 | 45 | 42 | 0 |
| 19 | 0 | 3 | 10 | 46 | 41 | 0 |
| 20 | 0 | 3 | 10 | 47 | 40 | 0 |
| 21 | 0 | 3 | 10 | 48 | 39 | 0 |
| 22 | 0 | 3 | 11 | 48 | 37 | 0 |
| 23 | 0 | 3 | 11 | 49 | 36 | 0 |
| 24 | 0 | 3 | 11 | 51 | 35 | 0 |
| 25 | 0 | 3 | 12 | 50 | 35 | 0 |
| 26 | 0 | 3 | 12 | 51 | 34 | 0 |
| 27 | 0 | 3 | 13 | 51 | 33 | 0 |
| 28 | 0 | 3 | 13 | 52 | 32 | 0 |
| 29 | 0 | 3 | 14 | 51 | 32 | 0 |
| 30 | 0 | 3 | 14 | 52 | 31 | 0 |
| 31 | 0 | 4 | 15 | 50 | 31 | 0 |
Wind in December
Winds average 7 km/h in December.
Across December, daily wind ranges from about 7 km/h on the calmest days to 8 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) | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| 1 | 7 | calm |
| 2 | 7 | calm |
| 3 | 7 | calm |
| 4 | 7 | calm |
| 5 | 7 | calm |
| 6 | 7 | calm |
| 7 | 7 | calm |
| 8 | 7 | calm |
| 9 | 7 | calm |
| 10 | 7 | calm |
| 11 | 7 | calm |
| 12 | 7 | calm |
| 13 | 7 | calm |
| 14 | 7 | calm |
| 15 | 7 | calm |
| 16 | 7 | calm |
| 17 | 7 | calm |
| 18 | 7 | calm |
| 19 | 7 | calm |
| 20 | 8 | calm |
| 21 | 8 | calm |
| 22 | 8 | calm |
| 23 | 8 | calm |
| 24 | 8 | calm |
| 25 | 8 | calm |
| 26 | 8 | calm |
| 27 | 8 | calm |
| 28 | 8 | calm |
| 29 | 8 | calm |
| 30 | 8 | calm |
| 31 | 8 | calm |
Sunrise & sunset in December
Daylight runs from about 11 h 18 min at the start of December to 11 h 12 min by month's end. The lit band spans sunrise to sunset each day.
Days shrink by about 6 minutes over December. Sunrise moves from 6:05 AM to 6:20 AM, and sunset from 5:22 PM to 5:34 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) | 11.3 | 11.3 | 11.3 | 11.3 | 11.3 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 | 11.2 |
| Sunrise (AM) | 6:05 | 6:06 | 6:07 | 6:07 | 6:08 | 6:08 | 6:09 | 6:09 | 6:10 | 6:10 | 6:11 | 6:11 | 6:12 | 6:12 | 6:13 | 6:13 | 6:14 | 6:14 | 6:15 | 6:15 | 6:16 | 6:16 | 6:17 | 6:17 | 6:18 | 6:18 | 6:19 | 6:19 | 6:19 | 6:20 | 6:20 |
| Sunset (PM) | 5:22 | 5:22 | 5:22 | 5:22 | 5:23 | 5:23 | 5:23 | 5:23 | 5:24 | 5:24 | 5:25 | 5:25 | 5:25 | 5:26 | 5:26 | 5:26 | 5:27 | 5:27 | 5:28 | 5:28 | 5:29 | 5:29 | 5:30 | 5:30 | 5:31 | 5:31 | 5:32 | 5:32 | 5:33 | 5:33 | 5:34 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 11.3 | 6:05 | 5:22 |
| 2 | 11.3 | 6:06 | 5:22 |
| 3 | 11.3 | 6:07 | 5:22 |
| 4 | 11.3 | 6:07 | 5:22 |
| 5 | 11.3 | 6:08 | 5:23 |
| 6 | 11.2 | 6:08 | 5:23 |
| 7 | 11.2 | 6:09 | 5:23 |
| 8 | 11.2 | 6:09 | 5:23 |
| 9 | 11.2 | 6:10 | 5:24 |
| 10 | 11.2 | 6:10 | 5:24 |
| 11 | 11.2 | 6:11 | 5:25 |
| 12 | 11.2 | 6:11 | 5:25 |
| 13 | 11.2 | 6:12 | 5:25 |
| 14 | 11.2 | 6:12 | 5:26 |
| 15 | 11.2 | 6:13 | 5:26 |
| 16 | 11.2 | 6:13 | 5:26 |
| 17 | 11.2 | 6:14 | 5:27 |
| 18 | 11.2 | 6:14 | 5:27 |
| 19 | 11.2 | 6:15 | 5:28 |
| 20 | 11.2 | 6:15 | 5:28 |
| 21 | 11.2 | 6:16 | 5:29 |
| 22 | 11.2 | 6:16 | 5:29 |
| 23 | 11.2 | 6:17 | 5:30 |
| 24 | 11.2 | 6:17 | 5:30 |
| 25 | 11.2 | 6:18 | 5:31 |
| 26 | 11.2 | 6:18 | 5:31 |
| 27 | 11.2 | 6:19 | 5:32 |
| 28 | 11.2 | 6:19 | 5:32 |
| 29 | 11.2 | 6:19 | 5:33 |
| 30 | 11.2 | 6:20 | 5:33 |
| 31 | 11.2 | 6:20 | 5:34 |
Solar energy in December
Average shortwave solar energy reaching the ground each day in December, about 5.54 kWh/m².
For context, solar energy here swings from a low near 5.23 kWh/m² to a high of 6.75 kWh/m² in March across the year — December's 5.54 kWh/m² sits near the bottom.
| 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) | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.6 | 5.6 | 5.6 | 5.6 | 5.6 | 5.6 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 5.5 | Bright |
| 2 | 5.5 | Bright |
| 3 | 5.5 | Bright |
| 4 | 5.5 | Bright |
| 5 | 5.5 | Bright |
| 6 | 5.5 | Bright |
| 7 | 5.5 | Bright |
| 8 | 5.5 | Bright |
| 9 | 5.5 | Bright |
| 10 | 5.5 | Bright |
| 11 | 5.5 | Bright |
| 12 | 5.5 | Bright |
| 13 | 5.5 | Bright |
| 14 | 5.5 | Bright |
| 15 | 5.5 | Bright |
| 16 | 5.5 | Bright |
| 17 | 5.5 | Bright |
| 18 | 5.5 | Bright |
| 19 | 5.5 | Bright |
| 20 | 5.5 | Bright |
| 21 | 5.5 | Bright |
| 22 | 5.5 | Bright |
| 23 | 5.5 | Bright |
| 24 | 5.5 | Bright |
| 25 | 5.5 | Bright |
| 26 | 5.6 | Bright |
| 27 | 5.6 | Bright |
| 28 | 5.6 | Bright |
| 29 | 5.6 | Bright |
| 30 | 5.6 | Bright |
| 31 | 5.6 | Bright |
Hazard calendar for Usulután
None of Usulután's seasonal hazards are active in December. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.
Usulután sits in the Atlantic hurricane belt; the season peaks August–October.
Usulután's monsoon runs May–October, when most of the year's rain falls.
Is December a good time to visit Usulután?
Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
December is a reasonable time to visit Usulután for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Usulután in December
From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In December, Usulután sees daytime highs around 31°C and nights near 23°C. Pack light clothes. Worth having: sun protection.
Sea temperature near Usulután in December
The nearest coast averages about 28°C in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 25 km away) is warmest in August at about 30°C and coldest in January near 28°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) | 28 | 28 | 28 | 29 | 30 | 30 | 30 | 30 | 30 | 29 | 29 | 28 |
| Comfort | Warm | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 28 | Warm |
| Feb | 28 | Tropical |
| Mar | 28 | Tropical |
| Apr | 29 | Tropical |
| May | 30 | Tropical |
| Jun | 30 | Tropical |
| Jul | 30 | Tropical |
| Aug | 30 | Tropical |
| Sep | 30 | Tropical |
| Oct | 29 | Tropical |
| Nov | 29 | Tropical |
| Dec | 28 | Tropical |
UV index in Usulután in December
Clear-sky midday UV in December peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Usulután peaks around March 20 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 14 at about 9 (very 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) | 10 | 12 | 13 | 13 | 12 | 13 | 12 | 11 | 12 | 11 | 9 | 9 |
| Level | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Very high | Very high |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 10 | Extreme |
| Feb | 12 | Extreme |
| Mar | 13 | Extreme |
| Apr | 13 | Extreme |
| May | 12 | Extreme |
| Jun | 13 | Extreme |
| Jul | 12 | Extreme |
| Aug | 11 | Extreme |
| Sep | 12 | Extreme |
| Oct | 11 | Extreme |
| Nov | 9 | Very high |
| Dec | 9 | Very high |
Air quality in Usulután in December
Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.
Air quality in Usulután is worst in April — around 34 µg/m³ PM2.5 (moderate), about 2.6× the cleanest month (January, 13 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) | 13 | 15 | 22 | 34 | 32 | 21 | 25 | 20 | 18 | 17 | 16 | 13 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 13 | Moderate |
| Feb | 15 | Moderate |
| Mar | 22 | Moderate |
| Apr | 34 | Moderate |
| May | 32 | Moderate |
| Jun | 21 | Moderate |
| Jul | 25 | Moderate |
| Aug | 20 | Moderate |
| Sep | 18 | Moderate |
| Oct | 17 | Moderate |
| Nov | 16 | Moderate |
| Dec | 13 | Moderate |
Where is Usulután?
Usulután sits at 13.3°N, 88.4°W, 100 m above sea level, in El Salvador. The nearest listed city is San Rafael Oriente, 11 km away.
Topography around Usulután
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Usulután.
Within 3 km, the terrain around Usulután has only modest variations in elevation — a maximum elevation change of 166 m around an average of 97 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,638 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,143 m.
The land around Usulután is covered by trees (53%) within 3 km, trees (45%) and grassland (26%) within 16 km, and trees (39%), water (33%) and grassland (20%) within 80 km.
El Salvador travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type A / B
- 115 V · 60 Hz
- Prices
- ≈ 41% of US
- price level, 2025
- GDP per capita
- $5,767
- 2025
- Happiness
- 6.6 / 10
- World Happiness, 2025
- Homicide rate
- 7.9
- per 100k, 2022
- Road deaths
- 20.9
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- Moderate
- EF EPI 523
- 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 Usulután (13.3447°, -88.4399°, elevation 100 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).