Usulután weather in May
In May, Usulután sees average daytime highs of 31°C and overnight lows near 25°C, with 220 mm of rain across 22.3 wet days and about 12.6 hours of daylight. It is the 5th-warmest and 5th-wettest month of the year here.
Highs ease over the month, from about 32°C in the first days to 30°C by the end. The sky is clear or mostly clear about 20% of the time in May, and the air most often feels miserable.
Daylight stretches from about 12 h 30 min at the start of May to 12 h 42 min by month's end. Set against the rest of the year, May is Usulután's 8th-clearest and 6th-windiest month. For the whole year in context, see Usulután's year-round climate.
- Daytime high
- 31°
- 5th warmest
- Overnight low
- 25°
- 12th coldest
- Rainfall
- 220 mm
- 22.3 wet days
- Daylight
- 12 h 36 min
- 5:32 AM – 6:08 PM
- Cloud cover
- 67%
- 8th clearest
- Wind
- 7 km/h
- 6th windiest
- Solar energy
- 6.1 kWh/m²
- Travel score
- 3.1
- 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 May
Highs ease over the month, from about 32°C in the first days to 30°C by the end.
A typical May day in Usulután reaches about 31°C in the afternoon and slips back to 25°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 34°C. Set against its neighbours, May runs about 1°C cooler than April and about 1°C warmer than June.
| 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) | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 30 | 30 | 30 | 30 |
| Avg low (°C) | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| 1 | 32 | 26 |
| 2 | 32 | 26 |
| 3 | 32 | 26 |
| 4 | 32 | 26 |
| 5 | 32 | 26 |
| 6 | 32 | 26 |
| 7 | 32 | 26 |
| 8 | 32 | 26 |
| 9 | 32 | 26 |
| 10 | 32 | 26 |
| 11 | 32 | 26 |
| 12 | 32 | 25 |
| 13 | 32 | 25 |
| 14 | 32 | 25 |
| 15 | 32 | 25 |
| 16 | 32 | 25 |
| 17 | 31 | 25 |
| 18 | 31 | 25 |
| 19 | 31 | 25 |
| 20 | 31 | 25 |
| 21 | 31 | 25 |
| 22 | 31 | 25 |
| 23 | 31 | 25 |
| 24 | 31 | 25 |
| 25 | 31 | 25 |
| 26 | 31 | 25 |
| 27 | 31 | 25 |
| 28 | 30 | 25 |
| 29 | 30 | 25 |
| 30 | 30 | 25 |
| 31 | 30 | 25 |
How May really feels in Usulután
Once humidity and wind are folded in, May 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 May is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Usulután weather by month
How May compares with the rest of the year at a glance. May is the 5th-warmest and 5th-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 May
The sky is clear or mostly clear about 20% of the time in May.
Beyond those clear spells, partly cloudy skies cover about 16% of May, with mostly cloudy or overcast conditions the remaining 64%. 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 (%) | 58 | 58 | 56 | 56 | 55 | 54 | 53 | 51 | 49 | 48 | 46 | 43 | 41 | 39 | 36 | 34 | 32 | 30 | 29 | 26 | 26 | 25 | 23 | 22 | 21 | 21 | 20 | 20 | 19 | 19 | 18 |
| Cloudier (%) | 42 | 42 | 44 | 44 | 45 | 46 | 47 | 49 | 51 | 52 | 54 | 57 | 59 | 61 | 64 | 66 | 68 | 70 | 71 | 74 | 74 | 75 | 77 | 78 | 79 | 79 | 80 | 80 | 81 | 81 | 82 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 58 | 42 |
| 2 | 58 | 42 |
| 3 | 56 | 44 |
| 4 | 56 | 44 |
| 5 | 55 | 45 |
| 6 | 54 | 46 |
| 7 | 53 | 47 |
| 8 | 51 | 49 |
| 9 | 49 | 51 |
| 10 | 48 | 52 |
| 11 | 46 | 54 |
| 12 | 43 | 57 |
| 13 | 41 | 59 |
| 14 | 39 | 61 |
| 15 | 36 | 64 |
| 16 | 34 | 66 |
| 17 | 32 | 68 |
| 18 | 30 | 70 |
| 19 | 29 | 71 |
| 20 | 26 | 74 |
| 21 | 26 | 74 |
| 22 | 25 | 75 |
| 23 | 23 | 77 |
| 24 | 22 | 78 |
| 25 | 21 | 79 |
| 26 | 21 | 79 |
| 27 | 20 | 80 |
| 28 | 20 | 80 |
| 29 | 19 | 81 |
| 30 | 19 | 81 |
| 31 | 18 | 82 |
Chance of precipitation in May
Usulután gets around 220 mm of rain over 22.3 wet days in May. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 71% and peaks near 86% 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 (%) | 52 | 53 | 55 | 56 | 58 | 59 | 60 | 61 | 62 | 63 | 65 | 66 | 67 | 69 | 70 | 72 | 74 | 75 | 77 | 78 | 79 | 81 | 82 | 83 | 84 | 84 | 85 | 85 | 86 | 86 | 86 |
| Rain chance (%) | |
|---|---|
| 1 | 52 |
| 2 | 53 |
| 3 | 55 |
| 4 | 56 |
| 5 | 58 |
| 6 | 59 |
| 7 | 60 |
| 8 | 61 |
| 9 | 62 |
| 10 | 63 |
| 11 | 65 |
| 12 | 66 |
| 13 | 67 |
| 14 | 69 |
| 15 | 70 |
| 16 | 72 |
| 17 | 74 |
| 18 | 75 |
| 19 | 77 |
| 20 | 78 |
| 21 | 79 |
| 22 | 81 |
| 23 | 82 |
| 24 | 83 |
| 25 | 84 |
| 26 | 84 |
| 27 | 85 |
| 28 | 85 |
| 29 | 86 |
| 30 | 86 |
| 31 | 86 |
Humidity in May
Most of May feels miserable — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, May lands in the miserable band about 49% of days. Sticky, muggy-or-worse air turns up on roughly 99% 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Humid (%) | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Muggy (%) | 4 | 4 | 4 | 4 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 2 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Oppressive (%) | 62 | 61 | 60 | 58 | 59 | 58 | 57 | 55 | 54 | 53 | 52 | 51 | 51 | 51 | 49 | 49 | 48 | 47 | 46 | 45 | 45 | 44 | 43 | 42 | 41 | 40 | 39 | 38 | 37 | 36 | 35 |
| Miserable (%) | 33 | 34 | 35 | 37 | 38 | 39 | 40 | 42 | 43 | 44 | 45 | 46 | 47 | 47 | 48 | 49 | 51 | 52 | 53 | 54 | 54 | 55 | 56 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 |
| Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|
| 1 | 1 | 4 | 62 | 33 |
| 2 | 1 | 4 | 61 | 34 |
| 3 | 1 | 4 | 60 | 35 |
| 4 | 1 | 4 | 58 | 37 |
| 5 | 0 | 3 | 59 | 38 |
| 6 | 0 | 3 | 58 | 39 |
| 7 | 0 | 3 | 57 | 40 |
| 8 | 0 | 3 | 55 | 42 |
| 9 | 0 | 3 | 54 | 43 |
| 10 | 0 | 3 | 53 | 44 |
| 11 | 0 | 3 | 52 | 45 |
| 12 | 0 | 3 | 51 | 46 |
| 13 | 0 | 2 | 51 | 47 |
| 14 | 0 | 2 | 51 | 47 |
| 15 | 0 | 2 | 49 | 48 |
| 16 | 0 | 2 | 49 | 49 |
| 17 | 0 | 1 | 48 | 51 |
| 18 | 0 | 1 | 47 | 52 |
| 19 | 0 | 1 | 46 | 53 |
| 20 | 0 | 1 | 45 | 54 |
| 21 | 0 | 1 | 45 | 54 |
| 22 | 0 | 1 | 44 | 55 |
| 23 | 0 | 1 | 43 | 56 |
| 24 | 0 | 0 | 42 | 58 |
| 25 | 0 | 0 | 41 | 59 |
| 26 | 0 | 0 | 40 | 60 |
| 27 | 0 | 0 | 39 | 61 |
| 28 | 0 | 0 | 38 | 62 |
| 29 | 0 | 0 | 37 | 63 |
| 30 | 0 | 0 | 36 | 64 |
| 31 | 0 | 0 | 35 | 65 |
Wind in May
Winds average 7 km/h in May.
Across May, daily wind ranges from about 6 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) | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 6 |
| 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 | 8 | calm |
| 2 | 8 | calm |
| 3 | 8 | calm |
| 4 | 8 | calm |
| 5 | 8 | calm |
| 6 | 8 | calm |
| 7 | 8 | calm |
| 8 | 8 | 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 | 7 | calm |
| 21 | 7 | calm |
| 22 | 7 | calm |
| 23 | 7 | calm |
| 24 | 7 | calm |
| 25 | 7 | calm |
| 26 | 7 | calm |
| 27 | 7 | calm |
| 28 | 7 | calm |
| 29 | 7 | calm |
| 30 | 7 | calm |
| 31 | 6 | calm |
Sunrise & sunset in May
Daylight runs from about 12 h 30 min at the start of May to 12 h 42 min by month's end. The lit band spans sunrise to sunset each day.
Days grow by about 12 minutes over May. Sunrise moves from 5:37 AM to 5:29 AM, and sunset from 6:05 PM to 6:13 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) | 12.5 | 12.5 | 12.5 | 12.5 | 12.5 | 12.5 | 12.5 | 12.5 | 12.6 | 12.6 | 12.6 | 12.6 | 12.6 | 12.6 | 12.6 | 12.6 | 12.6 | 12.6 | 12.6 | 12.6 | 12.7 | 12.7 | 12.7 | 12.7 | 12.7 | 12.7 | 12.7 | 12.7 | 12.7 | 12.7 | 12.7 |
| Sunrise (AM) | 5:37 | 5:36 | 5:36 | 5:36 | 5:35 | 5:35 | 5:34 | 5:34 | 5:34 | 5:33 | 5:33 | 5:33 | 5:32 | 5:32 | 5:32 | 5:32 | 5:31 | 5:31 | 5:31 | 5:31 | 5:31 | 5:30 | 5:30 | 5:30 | 5:30 | 5:30 | 5:30 | 5:30 | 5:30 | 5:30 | 5:29 |
| Sunset (PM) | 6:05 | 6:05 | 6:05 | 6:06 | 6:06 | 6:06 | 6:06 | 6:06 | 6:07 | 6:07 | 6:07 | 6:07 | 6:08 | 6:08 | 6:08 | 6:08 | 6:09 | 6:09 | 6:09 | 6:10 | 6:10 | 6:10 | 6:10 | 6:11 | 6:11 | 6:11 | 6:12 | 6:12 | 6:12 | 6:13 | 6:13 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 12.5 | 5:37 | 6:05 |
| 2 | 12.5 | 5:36 | 6:05 |
| 3 | 12.5 | 5:36 | 6:05 |
| 4 | 12.5 | 5:36 | 6:06 |
| 5 | 12.5 | 5:35 | 6:06 |
| 6 | 12.5 | 5:35 | 6:06 |
| 7 | 12.5 | 5:34 | 6:06 |
| 8 | 12.5 | 5:34 | 6:06 |
| 9 | 12.6 | 5:34 | 6:07 |
| 10 | 12.6 | 5:33 | 6:07 |
| 11 | 12.6 | 5:33 | 6:07 |
| 12 | 12.6 | 5:33 | 6:07 |
| 13 | 12.6 | 5:32 | 6:08 |
| 14 | 12.6 | 5:32 | 6:08 |
| 15 | 12.6 | 5:32 | 6:08 |
| 16 | 12.6 | 5:32 | 6:08 |
| 17 | 12.6 | 5:31 | 6:09 |
| 18 | 12.6 | 5:31 | 6:09 |
| 19 | 12.6 | 5:31 | 6:09 |
| 20 | 12.6 | 5:31 | 6:10 |
| 21 | 12.7 | 5:31 | 6:10 |
| 22 | 12.7 | 5:30 | 6:10 |
| 23 | 12.7 | 5:30 | 6:10 |
| 24 | 12.7 | 5:30 | 6:11 |
| 25 | 12.7 | 5:30 | 6:11 |
| 26 | 12.7 | 5:30 | 6:11 |
| 27 | 12.7 | 5:30 | 6:12 |
| 28 | 12.7 | 5:30 | 6:12 |
| 29 | 12.7 | 5:30 | 6:12 |
| 30 | 12.7 | 5:30 | 6:13 |
| 31 | 12.7 | 5:29 | 6:13 |
Solar energy in May
Average shortwave solar energy reaching the ground each day in May, about 6.1 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 — May's 6.1 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) | 6.6 | 6.6 | 6.6 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.4 | 6.4 | 6.4 | 6.3 | 6.3 | 6.3 | 6.2 | 6.2 | 6.1 | 6.0 | 6.0 | 6.0 | 5.9 | 5.9 | 5.8 | 5.8 | 5.7 | 5.7 | 5.7 | 5.7 | 5.6 | 5.6 | 5.6 |
| Level | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 6.6 | Intense |
| 2 | 6.6 | Intense |
| 3 | 6.6 | Intense |
| 4 | 6.5 | Intense |
| 5 | 6.5 | Intense |
| 6 | 6.5 | Intense |
| 7 | 6.5 | Intense |
| 8 | 6.5 | Intense |
| 9 | 6.4 | Intense |
| 10 | 6.4 | Intense |
| 11 | 6.4 | Intense |
| 12 | 6.3 | Intense |
| 13 | 6.3 | Intense |
| 14 | 6.3 | Intense |
| 15 | 6.2 | Intense |
| 16 | 6.2 | Intense |
| 17 | 6.1 | Intense |
| 18 | 6.0 | Intense |
| 19 | 6.0 | Intense |
| 20 | 6.0 | Bright |
| 21 | 5.9 | Bright |
| 22 | 5.9 | Bright |
| 23 | 5.8 | Bright |
| 24 | 5.8 | Bright |
| 25 | 5.7 | Bright |
| 26 | 5.7 | Bright |
| 27 | 5.7 | Bright |
| 28 | 5.7 | Bright |
| 29 | 5.6 | Bright |
| 30 | 5.6 | Bright |
| 31 | 5.6 | Bright |
Hazard calendar for Usulután
In May, Usulután sits inside its monsoon season. The full year is below, with each hazard's peak months called out.
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 May a good time to visit Usulután?
Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
May is a weaker month for outdoor sightseeing in Usulután.
What to pack for Usulután in May
From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In May, Usulután sees daytime highs around 31°C and nights near 25°C. Pack light clothes, rain gear and sun protection. About 22 days see rain.
Sea temperature near Usulután in May
The nearest coast averages about 30°C in May — 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 May
Clear-sky midday UV in May 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 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 May
Average fine-particle pollution (PM2.5) through the year — so you can see where May 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).