How warm is it in San Juan in August?

Daytime highs averaged 31.1 °C, night-time lows 27.0 °C. The highest value of the past 10 years was 33.0 °C (24 Aug 2023), the lowest 25.3 °C (31 Aug 2018).

How often does it rain in San Juan in August?

On average there were 24.7 rain days (at least 1 mm) with 118 mm of precipitation in total.

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San Juan weather in August: temperature & rain

Photo: P. Hughes · CC BY-SA 4.0

🇵🇷 Weather in San Juan in August

This is what the weather in San Juan (Puerto Rico) was like in August over the years 2017–2026.

Key facts at a glance

Prevailing weather: Light rain

Avg. daytime high

31.1 °C

30.5 °C – 31.8 °C

Avg. night-time low

27.0 °C

26.4 °C – 27.7 °C

Avg. rain days in period

24.7

80 % of days · ≥ 1.0 mm

Avg. precipitation in period

118 mm

70.2 mm – 205 mm

Avg. cloud cover

65 %

This data source has no sunshine hours – average cloud cover is shown instead.

Avg. sea temperature

–

Sea temperature unavailable for today (daily limit).

Extremes: Highest temperature 33.0 °C (24 Aug 2023) · Lowest temperature 25.3 °C (31 Aug 2018) · Avg. daily peak wind 22 km/h

Weather mix of all days

47Partly cloudy
7Cloudy
185Light rain
62Rain

Summary

On average 31.1 °C during the day and 27.0 °C at night.
On average 24.7 rain days (Rain day = at least 1.0 mm of precipitation) with 118 mm of precipitation in total.
Prevailing weather: Light rain.
Warmest year: 2026 (avg. 31.8 °C), coolest: 2017 (avg. 30.5 °C).
Wettest year: 2023 (205 mm), driest: 2026 (70.2 mm).
Extremes: 33.0 °C on 24 Aug 2023 and 25.3 °C on 31 Aug 2018.

Overall values from all 10 years. How is this calculated?

Temperatures per year

Average over your travel period

Precipitation & rain days

Year by year

2026
Avg. max31.8°Avg. min27.4°
Rain days
22 Rain days
Precipitation
70.2 mm
Avg. cloud cover
–
Sea temperature
–
Max 32.5 °C · Min 26.9 °C
2025
Avg. max31.4°Avg. min27.3°
Rain days
25 Rain days
Precipitation
96.8 mm
Avg. cloud cover
65 % cloudy
Sea temperature
–
Max 32.1 °C · Min 26.8 °C
2024
Avg. max30.7°Avg. min27.4°
Rain days
26 Rain days
Precipitation
148 mm
Avg. cloud cover
62 % cloudy
Sea temperature
–
Max 31.9 °C · Min 26.7 °C
2023
Avg. max31.6°Avg. min27.7°
Rain days
27 Rain days
Precipitation
205 mm
Avg. cloud cover
71 % cloudy
Sea temperature
–
Max 33.0 °C · Min 25.8 °C
2022
Avg. max30.9°Avg. min26.8°
Rain days
29 Rain days
Precipitation
89.3 mm
Avg. cloud cover
66 % cloudy
Sea temperature
–
Max 31.9 °C · Min 25.8 °C
2021
Avg. max30.7°Avg. min26.7°
Rain days
23 Rain days
Precipitation
107 mm
Avg. cloud cover
68 % cloudy
Sea temperature
–
Max 31.6 °C · Min 26.0 °C
2020
Avg. max31.1°Avg. min26.9°
Rain days
23 Rain days
Precipitation
128 mm
Avg. cloud cover
62 % cloudy
Sea temperature
–
Max 32.2 °C · Min 26.0 °C
2019
Avg. max31.2°Avg. min26.8°
Rain days
23 Rain days
Precipitation
82.6 mm
Avg. cloud cover
65 % cloudy
Sea temperature
–
Max 32.3 °C · Min 26.2 °C
2018
Avg. max30.7°Avg. min26.4°
Rain days
20 Rain days
Precipitation
95.9 mm
Avg. cloud cover
63 % cloudy
Sea temperature
–
Max 31.5 °C · Min 25.3 °C
2017
Avg. max30.5°Avg. min26.9°
Rain days
29 Rain days
Precipitation
154 mm
Avg. cloud cover
60 % cloudy
Sea temperature
–
Max 31.6 °C · Min 26.0 °C

Frequently asked questions

How warm is it in San Juan in August?: Daytime highs averaged 31.1 °C, night-time lows 27.0 °C. The highest value of the past 10 years was 33.0 °C (24 Aug 2023), the lowest 25.3 °C (31 Aug 2018).
How often does it rain in San Juan in August?: On average there were 24.7 rain days (at least 1 mm) with 118 mm of precipitation in total.

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Data sources

Weather data: Data obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program
Reanalysis (weather model constrained by observations) on a coarse grid of about 50 km. Values represent a large area and can differ from local conditions, especially on islands, coasts and in mountains. Snow depth is the model value for the grid cell, not the depth on the slopes. No sunshine duration.
Reanalysis (weather model constrained by observations)
Reanalysis values represent a grid cell (approx. 25–50 km) and may differ from local measurements on coasts, islands and in mountains.
Sea temperature: MUR SST data were provided by JPL under support by NASA MEaSUREs program; accessed via NOAA CoastWatch ERDDAP
Daily multi-scale ultra-high resolution (≈ 1 km) analysis of satellite measurements (infrared, microwave) and in-situ data. Represents the foundation temperature below the daily warm surface layer. (Satellite and in-situ analysis)
Place search: Natural Earth (public domain) · GeoNames (CC BY 4.0) / OpenStreetMap (ODbL)