5-day weather forecast St. Petersburg Sep 21, 2026

30°28° · Sunny

Weather forecast St. Petersburg Monday Sep 21, 2026: sunny, temperature from 28 °C to 30 °C.

Precipitation probability 62%. Wind up to 4 m/s (gusts 8.69 m/s). Air humidity 60–69%, atmospheric pressure 758–761 mm Hg, UV index up to 9.

Weather Alerts

MinorSep 16, 03:19 AM — Sep 18, 02:00 AMTranslate with Google

Small Craft Advisory issued September 16 at 3:19AM EDT until September 18 at 2:00AM EDT by NWS Tampa Bay Ruskin FL

Small Craft Advisory

* WHAT...Northeast winds 20 to 25 knots with gusts up to 30 knots and seas 4 to 6 feet expected. * WHERE...Portions of Gulf of America. * WHEN...From 5 PM this afternoon to 2 AM EDT Friday. * IMPACTS...Conditions will be hazardous to small craft.

Inexperienced mariners, especially those operating smaller vessels, should avoid navigating in hazardous conditions.

MinorSep 17, 03:35 AM — Sep 18, 02:00 AMTranslate with Google

Small Craft Advisory issued September 17 at 3:35AM EDT until September 18 at 2:00AM EDT by NWS Tampa Bay Ruskin FL

Small Craft Advisory

* WHAT...Northeast winds 20 to 25 knots with gusts up to 30 knots. * WHERE...Portions of Gulf of America. * WHEN...Until 2 AM EDT Friday. * IMPACTS...Conditions will be hazardous to small craft.

Inexperienced mariners, especially those operating smaller vessels, should avoid navigating in hazardous conditions.

5 days at a glance — tap a day to open it

Sunrise 07:18
Sunset 19:28

Waxing Gibbous82% illuminated
Moonrise 16:51 · Moonset 02:46

Chart

Table

← Sun, Sep 20

Mon, Sep 21, 2026

Tue, Sep 22 →

Forecast from 28 °C to 30 °C and precipitation

Temperature & Precipitation
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Temperature (°C)	29	29	29	29	28	28	28	28	29	29	29	29	30	30	30	30	30	30	30	29	29	29	29	29
Precipitation (mm/hr)	0.17	0	0.11	0	0.03	0	2.34	0	0.14	0	0	0	0	0	0	0	0	0	0	0	0	0.08	0.13	0

Cloud cover and precipitation probability

Cloud cover & Rain chance
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Cloud cover (%)	75	0	72	0	86	5	70	5	79	100	100	65	28	22	56	68	26	7	100	100	100	56	76	6
Rain chance (%)	20	3	18	4	16	5	62	5	21	15	15	9	5	5	8	9	5	4	15	15	15	17	19	4

Wind speed and direction

Wind & Wind gust
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Wind (m/s)	2	2.31	2.5	2.81	3.39	3.5	3	2.69	2.81	2.89	2.81	3	3.31	3.69	3.69	3.89	4	3.69	3.61	3.69	3.31	1.5	0.61	0.89
Wind gust (m/s)	2.11	2.42	5.5	2.81	3.42	3.72	3.33	3.11	3.22	3.22	3	6	6.31	8.69	6.69	6.89	8	6.69	7.61	8.69	6.31	4.5	1	4.89
Wind direction (°)	NE 40°	ENE 70°	E 88°	ESE 113°	SE 136°	SSE 158°	SSE 166°	S 175°	S 178°	S 182°	SSW 195°	SSW 210°	SW 218°	SW 219°	SW 219°	SW 222°	SW 232°	SW 236°	WSW 237°	WSW 248°	W 261°	WNW 288°	NNW 337°	WNW 301°

Air humidity

Humidity
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Humidity (%)	60	62	63	65	67	69	69	67	66	64	63	62	62	62	61	61	62	62	62	64	64	63	62	64

Atmospheric pressure

Pressure
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Pressure (mm Hg)	759	758	758	758	758	758	758	758	759	760	760	760	761	760	760	759	758	758	758	758	759	759	760	760

Ultraviolet index

UV Index
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
UV Index	0	0	0	0	0	0	0	0	0.1	0.9	2.6	5.1	7.4	9	8.7	7.1	4.7	2.5	0.9	0.1	0	0	0	0

Air quality & pollen

Air quality is available for the first three days only.

← Sun, Sep 20

Mon, Sep 21, 2026

Tue, Sep 22 →

St. Petersburg on the map

Data Sources & Methodology

Our weather forecasts are powered by a professional weather data provider that aggregates data from national weather services, satellite observations, radar networks, and over 80,000 weather stations worldwide. Forecast data is updated multiple times daily. We convert raw data into clear summaries — wind speed in m/s, pressure in mmHg — so you can plan your day with confidence.

Learn more about our methodology →