Florida sea level rise statistics show different rates around the state rather than one uniform statewide trend. NOAA tide gauges in the supplied table report mean relative sea level trends from 2.02 mm/yr at Fernandina Beach to 5.50 mm/yr at Port Manatee, with records ending in 2023. Other NOAA material reports 3.53 mm/yr at Key West Harbor and projects Florida Keys sea level rise of about 1.5 to 7 feet by 2100.
Table of contents
- Statewide measurements at a glance
- Atlantic and Keys tide-gauge records
- Southwest Florida and Tampa Bay
- Eastern Gulf Coast flooding
- What the Florida Keys projection measures
- Planning data and coastal islands
Statewide measurements at a glance
The NOAA Linear Relative Mean Sea Level Trends table gives a station-by-station view of relative sea level. The records have different starting years, lengths and completeness percentages, so the results are best read as measurements for individual locations. They are not a single Florida average.
Across the 10 Florida stations listed here, the reported mean trends span 2.02 to 5.50 mm/yr. The lowest listed rate is at Fernandina Beach, while the highest is at Port Manatee. The station records range from 48 years at Port Manatee to 111 years at Key West, and completeness ranges from 58% to 100%.
| Florida station | Record period | Years | Complete | Mean sea level trend |
|---|---|---|---|---|
| Fernandina Beach | 1897–2023 | 110 | 99% | 2.02 mm/yr |
| Mayport | 1928–2023 | 79 | 94% | 2.40 mm/yr |
| Virginia Key | 1931–2023 | 93 | 94% | 3.16 mm/yr |
| Vaca Key | 1971–2023 | 53 | 94% | 4.21 mm/yr |
| Key West | 1913–2023 | 111 | 99% | 2.61 mm/yr |
| Naples | 1965–2023 | 59 | 98% | 3.35 mm/yr |
| Fort Myers | 1965–2023 | 59 | 98% | 3.57 mm/yr |
| Port Manatee | 1976–2023 | 48 | 58% | 5.50 mm/yr |
| St. Petersburg | 1947–2023 | 77 | 100% | 3.09 mm/yr |
| Cedar Key | 1914–2023 | 110 | 88% | 2.35 mm/yr |
The record end year is 2023 for every station in this comparison. The start year differs substantially: Fernandina Beach begins in 1897, while Port Manatee begins in 1976. That difference matters when comparing a long historical record with a shorter one. A completeness percentage describes how much of a station’s stated record contains observations; it does not turn stations with different periods into directly interchangeable measurements.
Atlantic and Keys tide-gauge records
Fernandina Beach has the earliest starting year in this group, 1897, and a 99% complete record covering 110 years in the NOAA table. Its mean relative sea level trend is 2.02 mm/yr. Mayport’s record begins in 1928, covers 79 years, is 94% complete and has a mean trend of 2.40 mm/yr.
Virginia Key begins in 1931 and covers 93 years through 2023. NOAA reports 94% completeness and a mean trend of 3.16 mm/yr. The Virginia Key rate is higher than Fernandina Beach’s 2.02 mm/yr and Mayport’s 2.40 mm/yr, illustrating the geographic spread within Florida’s Atlantic-side measurements.
The Florida Keys stations have different results as well. Vaca Key’s record begins in 1971, covers 53 years and is 94% complete. Its mean trend is 4.21 mm/yr, the highest among the listed stations south of the mainland except for the Port Manatee value elsewhere in the table. Key West has the longest stated record in the group at 111 years, beginning in 1913. Its record is 99% complete and its NOAA table trend is 2.61 mm/yr.
A separate NOAA Coastal Flooding & the Florida Keys source reports a Key West Harbor sea level trend of 3.53 mm/yr, expressed there as 13.9 inches per 100 years. These are measurements identified for different named locations and source contexts: Key West in the Linear Relative Mean Sea Level Trends table is 2.61 mm/yr, while Key West Harbor in the Florida Keys material is 3.53 mm/yr. They should not be merged into one rate.
Southwest Florida and Tampa Bay
The southwest Florida stations in the NOAA table show mean trends above 3 mm/yr. Naples has a record from 1965 through 2023, a 59-year range, 98% completeness and a mean trend of 3.35 mm/yr. Fort Myers has the same start and end years, the same 59-year range and the same 98% completeness, but a higher mean trend of 3.57 mm/yr.
Port Manatee’s reported mean trend is 5.50 mm/yr. Its record begins in 1976 and ends in 2023, covering 48 years, with 58% completeness. The Port Manatee record is therefore the shortest and least complete among the 10 stations listed here, while also having the highest reported rate. That combination is important context for reading the number: the station’s trend is a local NOAA measurement, not a statewide forecast.
St. Petersburg, in Tampa Bay, has a record beginning in 1947 and ending in 2023. The NOAA table gives it a 77-year range, 100% completeness and a mean trend of 3.09 mm/yr. The 100% completeness is the highest value in this station group. NOAA’s 2023 Eastern Gulf High Tide Flooding Fact Sheet also gives St. Petersburg, Tampa Bay, a projected likely decadal range of 70 to 110 high tide flood days per year on average. That is a flooding outlook, not the same metric as a tide-gauge trend.
Cedar Key provides another Gulf Coast comparison. Its record starts in 1914, ends in 2023, covers 110 years and is 88% complete. The reported mean trend is 2.35 mm/yr. Cedar Key’s trend is close to the Fernandina Beach and Mayport measurements in this list, but its flooding outlook is notably different from a rate measured in millimeters per year.
Eastern Gulf Coast flooding
High tide flooding counts the days when water reaches a flooding threshold during high tides. In NOAA’s 2023 Eastern Gulf High Tide Flooding Fact Sheet, the Eastern Gulf Coast averaged 2 high tide flood days in the last year. Cedar Key recorded 5 high tide flood days in that period, the highest count on the Eastern Gulf Coast in the fact sheet.
NOAA predicts 2 to 6 high tide flood days for the Eastern Gulf Coast in the outlook year. The same fact sheet says this forecast implies a nearly 200% increase in flood days since 2000. The wording identifies this as an implication of the forecast, so it should be kept separate from the station trend measurements above.
The St. Petersburg outlook is much larger than the Eastern Gulf Coast average range: NOAA reports a projected likely decadal range of 70 to 110 high tide flood days per year on average for St. Petersburg, Tampa Bay. The range is decadal, meaning it describes an average over a decade rather than a claim that every individual year will contain exactly the same number of flood days.
These figures show why sea level rise statistics are not limited to one unit or one type of measurement. Tide gauges report a mean relative sea level trend in millimeters per year. Flooding fact sheets report days reaching a high-tide flooding threshold. Both relate to coastal water levels, but they answer different questions and should not be converted without additional information.
What the Florida Keys projection measures
NOAA’s Coastal Flooding & the Florida Keys material projects Florida Keys sea level rise of about 1.5 feet to 7 feet by 2100. This is a projection range, not a tide-gauge observation and not a statement that every Keys location will experience one identical amount. The endpoint is the year 2100, and the range is expressed in feet.
The same NOAA material reports the Key West Harbor trend as 3.53 mm/yr, or 13.9 inches per 100 years. The historical trend and the 2100 projection belong together as context but are not interchangeable. The first describes a measured rate associated with Key West Harbor; the second describes a future range for the Florida Keys.
The difference between a local rate and a regional projection is especially important when reading Florida coastal statistics. Fernandina Beach’s 2.02 mm/yr, Vaca Key’s 4.21 mm/yr and Port Manatee’s 5.50 mm/yr are station-specific values from the NOAA trend table. The 1.5-to-7-foot range is a forward-looking Florida Keys projection. Neither should be presented as the other.
Planning data and coastal islands
Florida’s planning data also has a geographic structure. The Florida Department of Environmental Protection identifies 10 regional planning councils and 5 regional planning areas in its Assessment Report of Regional Differences within Florida. Those counts describe the framework used for assessing regional differences; they are not counts of tide gauges or forecasts of sea level rise.
The Florida DEP Statewide Assessment page says Florida’s sea level rise dataset combines critical assets, topographical data and flood scenario data in one statewide inventory. This makes the dataset broader than a tide-gauge table: it includes assets, elevation-related information and scenario information for assessment purposes.
The USGS Florida island inundation data release includes 2,504 Florida coastal islands projected for inundation analysis. The number identifies islands included for analysis, not a claim that all 2,504 islands are already inundated or that each will experience the same future water level.
Together, these planning statistics show the different scales used to understand Florida’s exposure. NOAA station records provide local measurements through 2023. NOAA flooding material supplies recent counts, outlooks and a Florida Keys projection to 2100. Florida DEP organizes statewide and regional assessment information, while USGS identifies 2,504 islands for inundation analysis. Keeping the source, geography, measurement period and forecast status attached to each number is essential when comparing Florida sea level rise statistics.