Port St. John, FL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Port St. John, a community in Brevard County, Florida.
Today
91°F
Partly Sunny then Chance Showers And Thunderstorms
A chance of showers and thunderstorms between 1pm and 2pm, then showers and thunderstorms likely between 2pm and 5pm, then showers and thunderstorms. Partly sunny. High near 91, with temperatures falling to around 82 in the afternoon. Heat index values as high as 102. South southwest wind around 5 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
7-day forecast for Port St. John
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 91°F | Partly Sunny then Chance Showers And Thunderstorms | 5 mph SSW | 78% |
| Tonight | 74°F | Showers And Thunderstorms Likely then Mostly Cloudy | 0 to 5 mph S | 72% |
| Wednesday | 90°F | Partly Sunny then Chance Showers And Thunderstorms | 0 to 10 mph SE | 42% |
| Wednesday Night | 76°F | Chance Showers And Thunderstorms then Mostly Cloudy | 0 to 5 mph ESE | 42% |
| Thursday | 90°F | Chance Showers And Thunderstorms | 0 to 10 mph E | 45% |
| Thursday Night | 77°F | Chance Showers And Thunderstorms then Mostly Clear | 5 to 10 mph E | 43% |
| Friday | 90°F | Showers And Thunderstorms Likely | 10 to 15 mph E | 61% |
| Friday Night | 76°F | Chance Showers And Thunderstorms then Partly Cloudy | 5 to 10 mph ESE | 43% |
| Saturday | 91°F | Showers And Thunderstorms Likely | 5 to 10 mph ESE | 56% |
| Saturday Night | 76°F | Showers And Thunderstorms Likely then Partly Cloudy | 0 to 10 mph SE | 56% |
| Sunday | 92°F | Mostly Sunny then Chance Showers And Thunderstorms | 0 to 10 mph SE | 36% |
| Sunday Night | 76°F | Chance Showers And Thunderstorms then Mostly Clear | 0 to 10 mph SE | 36% |
| Monday | 93°F | Sunny then Chance Showers And Thunderstorms | 0 to 10 mph SE | 32% |
| Monday Night | 76°F | Chance Showers And Thunderstorms then Mostly Clear | 0 to 5 mph SE | 32% |
Forecast source: National Weather Service (api.weather.gov) for Port St. John (28.476, -80.810). Updated through the day.
Growing snapshot for Port St. John
Last spring frost
Jan 25
First fall frost
Jan 13
Growing season
362 days
Hardiness zone
10a
More local growing data for Port St. John: nearby ZIP 32927 weather · frost dates · planting calendar · Florida frost dates
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Climate data from the nearest NOAA station, Titusville, Fl (11.1 mi from Port St. John). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.