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San Juan weather

San Juan · 418,140 inhabitants · Thursday, October 29 · updated 13:15

Raining now Air: Good Moderate storm risk · Tomorrow, Sat, Sun

30°

Clear sky

Feels like 40°C

Wind

18 km/h

Gusts

18 km/h

Humidity

68 %

Pressure

1015 hPa

Clouds

10 %

Storm

Rise 06:22 Set 17:53 Day 11 h 30 min UV 8 · Very high

Morning, afternoon, evening

Trend

Afternoon

Mainly clear

32°29°

Feels like 42°

Wind ↑ ESE 22 km/h

Humidity 61 %

💧 0.1 mm

Evening

Mainly clear

28°27°

Feels like 39°

Wind ↑ SE 15 km/h

Gusts 22 km/h

Humidity 78 %

💧 0.2 mm

14:00

32°

0.1mm

ESE 15

17:00

29°

ESE 22

San Juan forecast in charts · next 7 days

The week ahead: highs and lows

▲ This week runs +2.4° warmer than usual

Highs Lows Usual for the season (1991–2020 average)

Hourly detail

Temperature (°C) Rain (mm) Wind (km/h)

San Juan climate: what a normal year looks like

The thermometer moves little from one season to the next: typical afternoon highs range from 27 °C in January to 30 °C in August, and the coolest nights (February) average 22 °C.

A normal year brings roughly 1,090 mm of rain — more than 55% of the towns of 20,000+ people we compared it with.

From 13 h 14 min of daylight in late June to 11 h 01 min in late December.

The coming week looks normal for October: forecast highs average 30 °C, against a usual 30 °C.

30-year averages (1991–2020)
Month	Typical high	Typical low	Rainfall
Jan	27 °C	22 °C	52 mm
Feb	27 °C	22 °C	41 mm
Mar	28 °C	22 °C	55 mm
Apr	28 °C	23 °C	86 mm
May	29 °C	24 °C	126 mm
Jun	30 °C	25 °C	78 mm
Jul	30 °C	25 °C	87 mm
Aug	30 °C	25 °C	102 mm
Sep	30 °C	25 °C	145 mm
Oct	30 °C	25 °C	135 mm
Nov	28 °C	24 °C	119 mm
Dec	27 °C	23 °C	60 mm
Whole year	29 °C	24 °C	1,090 mm

Source: our own processing of the ERA5 reanalysis (Copernicus/ECMWF) for 18.47° N, 66.11° W, 1991–2020. ERA5 averages over a 0.25° grid (about 25 km): hills, a coastline or the heat of the city itself can shift local values by a degree or two.

Air you breathe in San Juan: pollution and pollen

1/6

Good

European Air Quality Index (EAQI), from Copernicus CAMS

PM2.58µg/m³

PM1010µg/m³

Copernicus CAMS model, updated several times a day.

Rain radar around San Juan

Rain observed over the last two hours by official weather radars around San Juan, followed by the radar forecast for the next hour where the weather service provides one.

Rain radar Last two hours, then forecast where available · drag the timeline

No open weather radar covers San Juan yet: the map shows our hour-by-hour rain forecast (ICON, GFS).

Moon over San Juan

Waning gibbous

87 % illuminated · 18.3 days

Rise 16:52 Set 05:53

Fri 30/10 79%

Sat 31/10 69%

Sun 1/11 59%

Mon 2/11 49% Last quarter

Tue 3/11 38%

Wed 4/11 28%

Thu 5/11 19%

Fri 6/11 12%

Sat 7/11 6%

Sun 8/11 2%

Mon 9/11 0%

Tue 10/11 1% New moon

Moonrise and moonset in local time (America/Puerto_Rico); phase and lit fraction from a synodic calculation.

Look up a past day in San Juan

Curious about the weather in San Juan on a given day? Choose a date: we read it from the ERA5 reanalysis (ECMWF / Copernicus C3S), which runs until about a week ago.

San Juan weather at a glance

This page gathers everything about the weather in San Juan, San Juan: conditions now, the forecast for each part of the day and the trend for the coming week. At the moment the sky is “clear sky”, it is 30 °C (feels like 40 °C) and the wind blows at 18 km/h.

Expected range today: 26 °C to 32 °C and a dry sky; keep an eye on thunderstorms. The forecast comes from the AtmoAtlas engine, which combines ECMWF-AIFS, NOAA GFS and DWD ICON, adjusts cloud cover with METAR reports and uses convective energy (CAPE) to flag storms.

San Juan weather data for developers

Use the San Juan forecast in your own website or app: one JSON call returns weather, air quality, tides and sun and moon times. The free key needs no card.

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Where does this forecast come from? Our engine, checked every day against 1125 weather stations