Few U.S. towns have milder winter nights than Port St. John
July afternoons average 91°. A year here swings 39° from midwinter lows to midsummer highs. Precipitation is plentiful here, more than falls on 87% of U.S. towns. Plan time outside from October to April, when highs sit at 71–84°.
A year in Port St. John at a glance
Each month’s typical high and low, and what it brings.
What stands out about Port St. John’s climate
Compared with towns across the U.S., with Port St. John’s place in Florida beside it.
What a year in Port St. John feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
A freeze most winters
Frost and day counts come from NOAA’s station at Titusville, FL, 10 miles from the town’s center, at about the same height.
The 2023 USDA map puts Port St. John’s center in zone 10a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 32°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 51 inches of rain a year
June is the wettest month and December the driest. Rain falls on about 118 days a year. Snow is rare: about 0.0" in a normal year at Titusville, FL, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Port St. John
16% of the work is heating, so air conditioning is the bigger bill. No month averages under 55°.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Titusville, FL.
Living with Port St. John’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 10a. Frost comes about 5 winters in 10, so tender plants can often stay out through winter.
Months with highs of 62–84° and lows of 40° or more: January, February, March, April, October, November and December. 1.6 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Port St. John from natural hazards, hurricanes are the largest share (64%); heat waves, cold waves, winter storms and ice storms together are 1%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Port St. John and its neighbors
Every town next door is within a degree of Port St. John in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Port St. John’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Port St. John, FL | 52° | 91° | 51" | 0.0" |
| Galveston, TX | 48° | 89° | 52" | 0.1" |
| St. Marys, GA | 43° | 91° | 51" | 0.0" |
| Morgan City, LA | 44° | 91° | 60" | 0.0" |
| Hilton Head Island, SC | 41° | 90° | 49" | 0.0" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Port St. John averaged 1.5° warmer than the 1900s. The biggest change is in December (+2.2°).
A bigger shift than in 60% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Port St. John compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Port St. John’s place among Florida’s.
Port St. John weather by month
Highs, lows and precipitation from NOAA’s grid at Port St. John’s center; snow, wet days and snow on the ground from Titusville, FL. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 71° | 52° | 2.8" | 0.0" | 9 | 0 | 55° – 67° |
| February | 73° | 54° | 2.4" | 0.0" | 6 | 0 | 54° – 71° |
| March | 77° | 58° | 3.0" | 0.0" | 7 | 0 | 61° – 73° |
| April | 81° | 63° | 2.5" | 0.0" | 6 | 0 | 68° – 77° |
| May | 85° | 69° | 3.4" | 0.0" | 8 | 0 | 74° – 80° |
| June | 88° | 73° | 8.0" | 0.0" | 14 | 0 | 79° – 85° |
| July | 91° | 74° | 6.4" | 0.0" | 14 | 0 | 81° – 84° |
| August | 90° | 75° | 6.8" | 0.0" | 15 | 0 | 81° – 84° |
| September | 88° | 74° | 7.2" | 0.0" | 14 | 0 | 79° – 83° |
| October | 84° | 69° | 4.4" | 0.0" | 10 | 0 | 73° – 79° |
| November | 77° | 61° | 2.2" | 0.0" | 7 | 0 | 65° – 75° |
| December | 73° | 55° | 2.2" | 0.0" | 8 | 0 | 52° – 73° |
| Year | 81° | 65° | 51.2" | 0.0" | 118 | 0 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 52° to 73°. July is the most reliable, staying within 3°.
Where Port St. John’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Port St. John’s center.
- Snow: Titusville, FL.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Titusville, FL, 10 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Port St. John’s climate
What is the weather like in Port St. John?
A typical July afternoon reaches 91°, a January night drops to 52°, and snow is almost unheard of. Milder January nights than 98% of U.S. towns; hotter July afternoons than 80% of U.S. towns.
How cold does it get in Port St. John in winter?
January nights average 52°. About 2 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 55°.
How much snow does Port St. John get?
About 0.0 inches in a normal winter at Titusville, FL, so most winters see none.
How hot does it get in Port St. John?
July, with a typical high of 91° and a low of 74°. About 77 days a year reach 90° (Titusville, FL).
When is the first and last frost in Port St. John?
There is no reliable frost date: a 32° night comes in about 51% of winters at Titusville, FL, so most years bring a freeze but some pass without one.
What growing zone is Port St. John in?
Zone 10a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 32°.
What is the best time of year to visit Port St. John?
By one simple rule (highs of 62–84° and lows of 40° or more), January, February, March, April, October, November and December. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Port St. John getting warmer?
Yes: 1991–2020 averaged 1.5° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 60% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Port St. John.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.