Photo: LittleT889 · CC BY-SA 4.0Big Coppitt Key’s winters are milder and less snowy than most of the U.S.
A typical July afternoon reaches 90°, a January night drops to 65°, and snow is almost unheard of.
A year in Big Coppitt Key at a glance
Each month’s typical high and low, and what it brings.
What stands out about Big Coppitt Key’s climate
Compared with towns across the U.S., with Big Coppitt Key’s place in Florida beside it.
What a year in Big Coppitt Key feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
Frost is rare
Frost and day counts come from NOAA’s station at Key West Nas, FL, 2.0 miles from the town’s center, at about the same height.
The 2023 USDA map puts Big Coppitt Key’s center in zone 11b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 49°. Plant labels use the zone; frost dates tell you when to plant.
90° days by month
Average days at 90° or more
About 42 inches of rain a year
September is the wettest month and March the driest. Rain falls on about 102 days a year. Snow is rare: about 0.0" in a normal year at Key West Nas, FL, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Big Coppitt Key
1% 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 Key West Nas, FL.
Living with Big Coppitt Key’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 11b. Frost almost never comes, 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, November and December. 0.5 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Big Coppitt Key from natural hazards, hurricanes are the largest share (65%); heat waves, cold waves, winter storms and ice storms together are 1%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Big Coppitt Key and similar climates
TownRatings has no climate map of the towns around Big Coppitt Key yet.
Climates most like Big Coppitt Key’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 |
|---|---|---|---|---|
| Big Coppitt Key, FL | 65° | 90° | 42" | 0.0" |
| Waimanalo, HI | 65° | 84° | 42" | 0.0" |
| Corpus Christi, TX | 49° | 91° | 34" | 0.0" |
| St. Simons, GA | 43° | 91° | 49" | 0.0" |
| Hilton Head Island, SC | 41° | 90° | 49" | 0.0" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Big Coppitt Key averaged 1.6° warmer than the 1900s. The biggest change is in December (+2.3°).
A bigger shift than in 67% 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 Big Coppitt Key compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Big Coppitt Key’s place among Florida’s.
Big Coppitt Key weather by month
Highs, lows and precipitation from NOAA’s grid at Big Coppitt Key’s center; snow, wet days and snow on the ground from Key West Nas, FL. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 76° | 65° | 2.0" | 0.0" | 8 | 0 | 64° – 76° |
| February | 78° | 67° | 1.7" | 0.0" | 5 | 0 | 65° – 78° |
| March | 80° | 68° | 1.6" | 0.0" | 5 | 0 | 68° – 78° |
| April | 83° | 72° | 2.3" | 0.0" | 5 | 0 | 74° – 82° |
| May | 86° | 76° | 3.1" | 0.0" | 7 | 0 | 78° – 84° |
| June | 89° | 78° | 4.9" | 0.0" | 10 | 0 | 82° – 87° |
| July | 90° | 80° | 3.9" | 0.0" | 11 | 0 | 83° – 86° |
| August | 91° | 79° | 5.6" | 0.0" | 13 | 0 | 83° – 88° |
| September | 89° | 79° | 7.3" | 0.0" | 15 | 0 | 82° – 86° |
| October | 86° | 76° | 5.5" | 0.0" | 12 | 0 | 79° – 84° |
| November | 81° | 71° | 1.8" | 0.0" | 6 | 0 | 72° – 81° |
| December | 78° | 68° | 2.0" | 0.0" | 6 | 0 | 64° – 80° |
| Year | 84° | 73° | 41.7" | 0.0" | 102 | 0 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 64° to 80°. July is the most reliable, staying within 4°.
Where Big Coppitt Key’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 Big Coppitt Key’s center.
- Snow: Key West Nas, FL (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Key West Nas, FL, 2.0 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 Big Coppitt Key’s climate
What is the weather like in Big Coppitt Key?
A typical July afternoon reaches 90°, a January night drops to 65°, and snow is almost unheard of. Milder January nights than all but 42 U.S. towns; hotter July afternoons than 79% of U.S. towns.
How cold does it get in Big Coppitt Key in winter?
January nights average 65°. A night at 32° or below comes in only some winters (0.0 a year on average). In the coldest January of the last 30 years the month averaged 64°.
How much snow does Big Coppitt Key get?
About 0.0 inches in a normal winter at Key West Nas, FL, so most winters see none.
How hot does it get in Big Coppitt Key?
July, with a typical high of 90° and a low of 80°. About 80 days a year reach 90° (Key West Nas, FL).
When is the first and last frost in Big Coppitt Key?
Most years have no frost at all: a 32° night comes in about 0% of winters at Key West Nas, FL, usually in December or January.
What growing zone is Big Coppitt Key in?
Zone 11b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 49°.
What is the best time of year to visit Big Coppitt Key?
By one simple rule (highs of 62–84° and lows of 40° or more), January, February, March, April, November and December. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Big Coppitt Key getting warmer?
Yes: 1991–2020 averaged 1.6° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 67% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Big Coppitt Key.
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.