5-day weather forecast St. Petersburg Sep 21, 2026
30°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
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.
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
Sunset 19:28
Waxing Gibbous82% illuminated
Moonrise 16:51 · Moonset 02:46
Moonrise 16:51 · Moonset 02:46
Chart
Table
| Time | Weather | Temperature | Rain chance | Cloud cover | Humidity | Pressure | Wind | UV Index |
|---|---|---|---|---|---|---|---|---|
| 00:00 |  Patchy rain possible | 29 °C | 20% (0.17 mm/hr) | 75% | 60% | 759 mm Hg | NE 40° 2 (2.11) m/s | 0 |
| 01:00 |  Clear | 29 °C | 3% | 0% | 62% | 758 mm Hg | ENE 70° 2.31 (2.42) m/s | 0 |
| 02:00 | Patchy rain possible | 29 °C | 18% (0.11 mm/hr) | 72% | 63% | 758 mm Hg | E 88° 2.5 (5.5) m/s | 0 |
| 03:00 | Clear | 29 °C | 4% | 0% | 65% | 758 mm Hg | ESE 113° 2.81 (2.81) m/s | 0 |
| 04:00 | Patchy rain possible | 28 °C | 16% (0.03 mm/hr) | 86% | 67% | 758 mm Hg | SE 136° 3.39 (3.42) m/s | 0 |
| 05:00 | Clear | 28 °C | 5% | 5% | 69% | 758 mm Hg | SSE 158° 3.5 (3.72) m/s | 0 |
| 06:00 | Patchy rain possible | 28 °C | 62% (2.34 mm/hr) | 70% | 69% | 758 mm Hg | SSE 166° 3 (3.33) m/s | 0 |
| 07:00 | Clear | 28 °C | 5% | 5% | 67% | 758 mm Hg | S 175° 2.69 (3.11) m/s | 0 |
| 08:00 |  Patchy rain possible | 29 °C | 21% (0.14 mm/hr) | 79% | 66% | 759 mm Hg | S 178° 2.81 (3.22) m/s | 0.1 |
| 09:00 |  Overcast | 29 °C | 15% | 100% | 64% | 760 mm Hg | S 182° 2.89 (3.22) m/s | 0.9 |
| 10:00 | Overcast | 29 °C | 15% | 100% | 63% | 760 mm Hg | SSW 195° 2.81 (3) m/s | 2.6 |
| 11:00 |  Cloudy | 29 °C | 9% | 65% | 62% | 760 mm Hg | SSW 210° 3 (6) m/s | 5.1 |
| 12:00 |  Partly cloudy | 30 °C | 5% | 28% | 62% | 761 mm Hg | SW 218° 3.31 (6.31) m/s | 7.4 |
| 13:00 | Sunny | 30 °C | 5% | 22% | 62% | 760 mm Hg | SW 219° 3.69 (8.69) m/s | 9 |
| 14:00 | Partly cloudy | 30 °C | 8% | 56% | 61% | 760 mm Hg | SW 219° 3.69 (6.69) m/s | 8.7 |
| 15:00 | Cloudy | 30 °C | 9% | 68% | 61% | 759 mm Hg | SW 222° 3.89 (6.89) m/s | 7.1 |
| 16:00 | Partly cloudy | 30 °C | 5% | 26% | 62% | 758 mm Hg | SW 232° 4 (8) m/s | 4.7 |
| 17:00 | Sunny | 30 °C | 4% | 7% | 62% | 758 mm Hg | SW 236° 3.69 (6.69) m/s | 2.5 |
| 18:00 | Overcast | 30 °C | 15% | 100% | 62% | 758 mm Hg | WSW 237° 3.61 (7.61) m/s | 0.9 |
| 19:00 | Overcast | 29 °C | 15% | 100% | 64% | 758 mm Hg | WSW 248° 3.69 (8.69) m/s | 0.1 |
| 20:00 |  Overcast | 29 °C | 15% | 100% | 64% | 759 mm Hg | W 261° 3.31 (6.31) m/s | 0 |
| 21:00 | Patchy rain possible | 29 °C | 17% (0.08 mm/hr) | 56% | 63% | 759 mm Hg | WNW 288° 1.5 (4.5) m/s | 0 |
| 22:00 | Patchy rain possible | 29 °C | 19% (0.13 mm/hr) | 76% | 62% | 760 mm Hg | NNW 337° 0.61 (1) m/s | 0 |
| 23:00 | Clear | 29 °C | 4% | 6% | 64% | 760 mm Hg | WNW 301° 0.89 (4.89) m/s | 0 |
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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.