Feature
Florida sees about 20.8 cloud-to-ground flashes per square mile a year — roughly 40 times Washington's rate.
All 48 measured states plus D.C. ranked by cloud-to-ground lightning flash density, with per-mile and per-km figures and total flash counts from Vaisala's NLDN.
By Nora Callahan · · 1 min read
Lightning risk is about density, not headline totals. Texas records the most cloud-to-ground flashes of any state, but it is so large that its per-square-mile rate lands mid-pack, while Florida, Louisiana, and Mississippi top the list on a Gulf Coast band of humid, storm-fed air. The table and chart below rank all 48 measured states plus D.C. by flashes per square mile per year, averaged over 2009–2018 from Vaisala’s National Lightning Detection Network. Alaska and Hawaii sit outside that network and are not measured.
Sort and hover. Click any column to reorder by rank, density, or total flashes, and hover a bar for its per-square-kilometer value and rank.
Every figure below is transcribed from one Vaisala Cloud-To-Ground Flash Density datasheet built on the U.S. National Lightning Detection Network (NLDN), averaged over the ten years 2009–2018. Density is what makes a state “lightning-prone”: Florida records about 40 times more flashes per square mile than Washington. Total counts tell a different story — Texas logs the most flashes of any state, but it is so large that its density lands mid-pack.
The Full Ranking — 48 States Plus D.C.
Click a column header to sort; hover a header for what it means. Rank is Vaisala’s own, by flashes per square mile. Alaska and Hawaii sit outside NLDN coverage and are not measured.
| Rank | State | Flashes / Mi²·Yr | Flashes / Km²·Yr | Avg Flashes / Yr | Flashes In 2018 |
|---|---|---|---|---|---|
| 1 | Florida | 20.8 | ~8.0 | 1,189,873 | 1,385,710 |
| 2 | Louisiana | 18.9 | ~7.3 | 875,136 | 854,871 |
| 3 | Mississippi | 16.1 | ~6.2 | 768,126 | 678,707 |
| 4 | Oklahoma | 15.8 | ~6.1 | 1,102,399 | 958,925 |
| 5 | Arkansas | 15.7 | ~6.1 | 837,978 | 778,168 |
| 6 | Missouri | 14.1 | ~5.4 | 981,351 | 711,222 |
| 7 | Alabama | 13.9 | ~5.4 | 720,780 | 631,644 |
| 8 | Illinois | 12.7 | ~4.9 | 716,885 | 533,158 |
| 9 | Kentucky | 12.5 | ~4.8 | 502,715 | 388,292 |
| 10 | Kansas | 12.5 | ~4.8 | 1,023,177 | 928,760 |
| 11 | Tennessee | 12.2 | ~4.7 | 511,650 | 436,018 |
| 12 | Indiana | 11.3 | ~4.4 | 406,902 | 256,464 |
| 13 | South Carolina | 11.2 | ~4.3 | 346,282 | 305,251 |
| 14 | Iowa | 11.1 | ~4.3 | 625,437 | 651,375 |
| 15 | Texas | 11.0 | ~4.2 | 2,923,584 | 2,483,805 |
| 16 | Georgia | 10.9 | ~4.2 | 642,203 | 693,776 |
| 17 | Nebraska | 10.1 | ~3.9 | 780,934 | 800,019 |
| 18 | Ohio | 8.8 | ~3.4 | 365,476 | 234,214 |
| 19 | D.C. | 8.4 | ~3.2 | 571 | 524 |
| 20 | North Carolina | 8.3 | ~3.2 | 412,340 | 345,236 |
| 21 | Maryland | 7.4 | ~2.9 | 73,218 | 60,381 |
| 22 | South Dakota | 7.0 | ~2.7 | 540,604 | 641,487 |
| 23 | Virginia | 6.8 | ~2.6 | 271,175 | 260,957 |
| 24 | West Virginia | 6.6 | ~2.5 | 159,353 | 148,510 |
| 25 | New Mexico | 6.0 | ~2.3 | 731,776 | 699,719 |
| 26 | Delaware | 5.8 | ~2.2 | 11,487 | 8,614 |
| 27 | Pennsylvania | 5.3 | ~2.0 | 241,330 | 197,654 |
| 28 | New Jersey | 5.3 | ~2.0 | 40,286 | 35,383 |
| 29 | Minnesota | 5.0 | ~1.9 | 425,932 | 531,162 |
| 30 | Wisconsin | 4.9 | ~1.9 | 274,963 | 279,864 |
| 31 | North Dakota | 4.9 | ~1.9 | 342,547 | 509,862 |
| 32 | Colorado | 4.8 | ~1.9 | 496,722 | 467,855 |
| 33 | Arizona | 4.7 | ~1.8 | 539,689 | 574,035 |
| 34 | Michigan | 3.8 | ~1.5 | 220,635 | 180,764 |
| 35 | Connecticut | 3.3 | ~1.3 | 16,316 | 16,992 |
| 36 | New York | 3.1 | ~1.2 | 150,157 | 91,790 |
| 37 | Wyoming | 2.7 | ~1.0 | 265,681 | 278,439 |
| 38 | Massachusetts | 2.4 | ~0.9 | 19,177 | 19,613 |
| 39 | Vermont | 2.2 | ~0.8 | 21,261 | 10,286 |
| 40 | Utah | 2.2 | ~0.8 | 187,410 | 143,341 |
| 41 | New Hampshire | 1.9 | ~0.7 | 17,238 | 13,504 |
| 42 | Montana | 2.1 | ~0.8 | 308,166 | 297,344 |
| 43 | Rhode Island | 2.1 | ~0.8 | 2,210 | 1,223 |
| 44 | Maine | 1.2 | ~0.5 | 40,380 | 32,902 |
| 45 | Nevada | 1.2 | ~0.5 | 129,580 | 116,394 |
| 46 | Idaho | 1.0 | ~0.4 | 79,327 | 69,840 |
| 47 | California | 0.5 | ~0.2 | 81,689 | 56,106 |
| 48 | Oregon | 0.5 | ~0.2 | 46,190 | 39,799 |
| 49 | Washington | 0.4 | ~0.2 | 24,490 | 15,921 |
Flash Density By State, Ranked
Cloud-to-ground flashes per square mile per year, 2009–2018 average, sorted high to low. Hover a bar for its per-km² value and rank.
Sources
- Cloud-To-Ground Flash Density by State, 2009–2018 (Vaisala datasheet, hosted by NWS)Vaisala / NWSThe primary table transcribed here: rank, flashes per square mile, average flashes per year (2009–2018), and 2018 flash counts for every measured state and D.C. Measured by the National Lightning Detection Network; updated February 2019.
- Vaisala Interactive Lightning Density MapVaisalaInteractive per-area flash-density map from the same NLDN/GLD360 networks; used to sanity-check the state ranking.
- The Annual Lightning Report 2025Vaisala XweatherMost recent annual report (published Jan 2026, total-lightning basis). Confirms the ranking is stable: Texas leads on total count while Florida remains the density leader; Rhode Island lowest.
- 2025 Report Press Release: U.S. Lightning Hits Eight-Year HighVaisalaSummary release for the 2025 report, with top-state density and count figures for cross-checking recency.
Method
The full 49-row table (48 states plus D.C.) is transcribed directly from Vaisala’s “Number of Cloud-To-Ground Flashes by State” and “Rank of Cloud-To-Ground Flash Densities by State” datasheet, extracted from the source PDF hosted on weather.gov rather than retyped from a summary article. Density is reported by Vaisala in flashes per square mile; the per-square-kilometer column is a straight conversion (per-mi² ÷ 2.59) and is flagged with a leading ~ to signal it carries the source’s rounding. Counts are cloud-to-ground flashes only — the NLDN’s measurement basis — not the total-lightning (in-cloud + cloud-to-ground) events used in Vaisala’s newer annual reports, which is why the count magnitudes here are smaller than 2024–2025 headline numbers. The chart is sorted strictly by density so bar lengths run monotonically top to bottom; the table keeps Vaisala’s published rank number.
Gaps
Alaska and Hawaii are not shown: the National Lightning Detection Network does not cover them, so no density or count exists in this source (dash, not zero). The data is a 2009–2018 average, updated February 2019 — the most complete state-by-state cloud-to-ground density table Vaisala publishes; year-to-year figures shift (Vaisala’s 2025 total-lightning report shows the same states clustered at the top and bottom), but a matching full 50-state per-km² density table for a single recent year is not published openly, so this ten-year average is the citable ground truth. The published sheet ranks New Hampshire (1.9) above Montana (2.1); that ordering slip is preserved in the Rank column and explained above rather than silently corrected. D.C.’s density (8.4/mi²) rides on a tiny 61-square-mile area and a 571-flash annual average, so its rank is statistically noisy compared with full-size states.