San Marcos · first 14 days — live forecast · rest of month — climate corridor
🗺️ 14-day forecast map
San Marcos & neighbors — hit play
Every city on the map carries real forecast data from the same models as its city page, refreshed several times a day. The icon is the day's overall look; the number is the afternoon high.
Next 14 days at a glance
from the model forecast
Hottest day
93°
Mon, Sep 7
Coldest night
59°
Wed, Sep 2
Days with precip
2 / 14
of 14 forecast days
Nicest day
Sun, Sep 13
mild, dry, light wind
The next 4 weekends
plan ahead
Sat 5 – Sun 6 Sep
80° 63°
79% precip chance
Sat 12 – Sun 13 Sep
77° 65°
17% precip chance
Sat 19 – Sun 20 Sep
77° 64°
typical range
Sat 26 – Sun 27 Sep
80° 65°
typical range
30 days — San Marcos
14 forecast + 16 climatology
Tue · Today Sunny
87°62°6%⌄
Wind14 mph W
Gusts23 mph
UV index10 – Very high
Precip chance6%
Sunrise06:23
Sunset19:14
Wed · Tomorrow Sunny
81°59°3%⌄
Wind14 mph SW
Gusts24 mph
UV index9 – Very high
Precip chance3%
Sunrise06:23
Sunset19:12
Thursday 3/9 Sunny
78°60°4%⌄
Wind14 mph SW
Gusts22 mph
UV index9 – Very high
Precip chance4%
Sunrise06:24
Sunset19:11
Friday 4/9 Sunny
78°61°6%⌄
Wind14 mph SW
Gusts25 mph
UV index9 – Very high
Precip chance6%
Sunrise06:25
Sunset19:10
Saturday 5/9 Mostly cloudy
80°63°3.2 mm⌄
Wind8 mph S
Gusts15 mph
UV index6 – High
Precip chance66%
Sunrise06:25
Sunset19:08
Sunday 6/9 Showers
76°72°3.2 mm⌄
Wind9 mph N
Gusts14 mph
UV index5 – Moderate
Precip chance79%
Sunrise06:26
Sunset19:07
Monday 7/9 Mostly cloudy
93°76°11%⌄
Wind12 mph N
Gusts22 mph
UV index8 – Very high
Precip chance11%
Sunrise06:27
Sunset19:06
Tuesday 8/9 Sunny
84°75°6%⌄
Wind12 mph W
Gusts19 mph
UV index7 – High
Precip chance6%
Sunrise06:27
Sunset19:04
Wednesday 9/9 Sunny
85°72°5%⌄
Wind13 mph W
Gusts21 mph
UV index7 – High
Precip chance5%
Sunrise06:28
Sunset19:03
Thursday 10/9 Sunny
81°69°5%⌄
Wind12 mph SW
Gusts23 mph
UV index7 – High
Precip chance5%
Sunrise06:29
Sunset19:02
Friday 11/9 Sunny
76°67°17%⌄
Wind13 mph SW
Gusts24 mph
UV index6 – High
Precip chance17%
Sunrise06:29
Sunset19:00
Saturday 12/9 Partly cloudy
76°67°17%⌄
Wind12 mph SW
Gusts21 mph
UV index6 – High
Precip chance17%
Sunrise06:30
Sunset18:59
Sunday 13/9 Sunny
77°65°6%⌄
Wind13 mph W
Gusts20 mph
UV index6 – High
Precip chance6%
Sunrise06:30
Sunset18:58
Monday 14/9 Sunny
84°69°5%⌄
Wind9 mph W
Gusts20 mph
UV index7 – High
Precip chance5%
Sunrise06:31
Sunset18:56
Tuesday 15/9 Light rain (climatological)
83°68°1.1 mm⌄
Day≈78–89°
Night≈63–74°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 16/9 Partly cloudy (climatological)
84°69°20%⌄
Day≈78–89°
Night≈63–74°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 17/9 Partly cloudy (climatological)
88°71°20%⌄
Day≈83–94°
Night≈66–77°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 18/9 Light rain (climatological)
81°67°2.0 mm⌄
Day≈75–86°
Night≈61–72°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 19/9 Partly cloudy (climatological)
77°64°20%⌄
Day≈71–82°
Night≈59–70°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 20/9 Partly cloudy (climatological)
77°64°20%⌄
Day≈72–82°
Night≈59–70°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 21/9 Light rain (climatological)
80°66°0.8 mm⌄
Day≈75–85°
Night≈61–72°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 22/9 Partly cloudy (climatological)
83°68°20%⌄
Day≈77–88°
Night≈62–73°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 23/9 Partly cloudy (climatological)
85°69°20%⌄
Day≈80–90°
Night≈64–74°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 24/9 Light rain (climatological)
86°70°1.4 mm⌄
Day≈81–92°
Night≈65–76°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 25/9 Partly cloudy (climatological)
85°69°20%⌄
Day≈80–91°
Night≈64–75°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 26/9 Partly cloudy (climatological)
80°66°20%⌄
Day≈75–85°
Night≈61–72°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 27/9 Light rain (climatological)
79°65°1.8 mm⌄
Day≈73–84°
Night≈60–71°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 28/9 Partly cloudy (climatological)
76°64°20%⌄
Day≈71–81°
Night≈58–69°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 29/9 Partly cloudy (climatological)
82°68°20%⌄
Day≈77–88°
Night≈62–73°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 30/9 Light rain (climatological)
84°69°1.4 mm⌄
Day≈79–89°
Night≈63–74°
Precip≈0.6 in / September
(climatological)Typical range for these dates · 1991–2020
How does a 30-day outlook work?
The first 14 days are a live model forecast. The back half of the month shows the typical range for those dates — useful for planning, not a literal prediction.
First 14 days: a real forecast, blended from NBM, ECMWF and GFS runs. Trust it most inside three days; by the second week treat it as a lean, not a promise.
Rest of the month: past day 14 we stop pretending to forecast and switch to the climate corridor — the range those dates have produced over three decades computed directly for San Marcos, with mild week-to-week wiggle.
Good question for this page: "Is late August usually humid in Chicago?" Bad question: "Do I need an umbrella on the 29th?" — three weeks out no one knows, and that's the honest answer.