NHC HURDAT2 · SPC Tornado Database
Hurricanes and Tornadoes That Hit Half Moon Bay, CA
Every tropical system within 75 miles since 1851 and every tornado within 25 miles since 1950.
Data: NOAA NHC HURDAT2 and NOAA SPC tornado and hail reports, through 2025 · Updated
No tropical storm or hurricane has passed within 75 miles of Half Moon Bay, California since records began in 1851. Since 1950, 9 tornadoes have touched down within 25 miles, 0 of them rated EF3 or stronger.
- Hurricanes
- 0
- Tropical storms
- 0
- Tornadoes
- 9
- EF3 or stronger
- 0
within 75 mi, since 1851
below hurricane strength
within 25 mi, since 1950
no recorded deaths
What the records show for Half Moon Bay
The highest rating among the 9 tornadoes within 25 miles is F2, reached 2 times; the most recent, on May 5, 1998, came within 24 miles. Of the 9, one had a path within 5 miles of the city centre, and one has come since 2000. The most recent tornado was on March 20, 2005. Of the 705 California cities on this site, 63% have more tornadoes within 25 miles than Half Moon Bay. Hail has been reported within 10 miles 8 times since 2017, with stones up to 0.25 inches. Half Moon Bay has more hail reports within 10 miles than 82% of the 705 California cities.
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Tornadoes within 25 miles of Half Moon Bay
By decade
- 2000s1
- 1990s5
- 1980s1
- 1950s2
| Date | Rating | Distance | Path | Killed / injured |
|---|---|---|---|---|
| May 5, 1998 | F2 | 24 mi | 0.6 mi | 0 / 1 |
| Jan 11, 1951 | F2 | 19 mi | 5.7 mi | 0 / 0 |
| Mar 20, 2005 | F1 | 12 mi | 3 mi | 0 / 0 |
| May 5, 1998 | F1 | 19 mi | 0.3 mi | 0 / 1 |
| Apr 1, 1958 | F1 | 11 mi | 0.2 mi | 0 / 0 |
| Feb 7, 1998 | F0 | in town | 0.2 mi | 0 / 0 |
| Feb 6, 1998 | F0 | 24 mi | 0.1 mi | 0 / 0 |
| Dec 17, 1992 | F0 | 24 mi | 0.2 mi | 0 / 0 |
| Mar 10, 1986 | F0 | 5 mi | 0.2 mi | 0 / 0 |
The strongest 9 of 9, by rating and then by deaths. Ratings before February 2007 are on the original Fujita scale.
Hail in Half Moon Bay
The Storm Prediction Center has 8 hail reports within 10 miles of Half Moon Bay since 2017. None of them reached 1 inch. The largest size, 0.25 inches, was reported on 8 days, most recently March 30, 2024. The most recent report is from March 30, 2024.
Source: NOAA Storm Prediction Center severe weather reports, data through 2025.
Weather by month in Half Moon Bay
The nearest NOAA station with 1991–2020 climate normals is Half Moon Bay, CA, in Half Moon Bay at 27 feet. August is the warmest, with an average high of 66°F and low of 54°F; December is the coolest, at 59°F and 43°F. December is the wettest at 5.2 inches of precipitation on average and July the driest at 0.1 inches; the year adds up to 26.1 inches over 49 days with at least a tenth of an inch. Highs reach 90°F on about 1 days a year. Lows fall below freezing on about 5 nights a year. That 26.1 inches is more than at 172 of the 226 California stations used on this site (76%). Moss Beach, 5 miles northwest, has its own station (Pacifica 4 SSE, CA): 32.0 inches a year, 5.9 more than here, and an August average high of 71°F against 66°F.
Water temperature at the NOAA tide station Redwood City, CA, 13 miles east, averaged 74°F in August and 54°F in January over 2021–2025. No month averaged 80°F. Sea level at the Redwood City tide gauge, 13 miles from Half Moon Bay, has risen 1.08 ± 0.25 inches per decade from 1974 to 2025, NOAA's linear trend; at that pace it is 10.8 inches in a hundred years. That is faster than at 62 of the 144 U.S. gauges with a NOAA trend.
| Month | High °F | Low °F | Precip. in | Days ≥ 0.1" | Water °F |
|---|---|---|---|---|---|
| Jan | 59 | 43 | 5.1 | 8 | 54 |
| Feb | 60 | 43 | 4.7 | 9 | 55 |
| Mar | 60 | 44 | 3.7 | 8 | 58 |
| Apr | 61 | 45 | 1.8 | 5 | 62 |
| May | 62 | 48 | 1.0 | 2 | 67 |
| Jun | 64 | 50 | 0.4 | 1 | 70 |
| Jul | 65 | 53 | 0.1 | 0 | 73 |
| Aug | 66 | 54 | 0.2 | 0 | 74 |
| Sep | 66 | 51 | 0.2 | 0 | 73 |
| Oct | 66 | 48 | 1.3 | 2 | 69 |
| Nov | 63 | 45 | 2.4 | 5 | 60 |
| Dec | 59 | 43 | 5.2 | 8 | 55 |
| Year | 63 | 47 | 26.1 | 49 | 64 |
Averages for 1991–2020 at Half Moon Bay, CA (27 ft), from NOAA NCEI U.S. Climate Normals; water temperature: average of hourly readings 2021–2025 at the NOAA tide station Redwood City, CA, from NOAA Tides & Currents. Normals describe the station; the farther a place is from it, and the bigger the difference in height, the more its weather can differ.
Floods, thunderstorm wind and lightning near Half Moon Bay
Since 1996, the National Weather Service has logged 37 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Half Moon Bay: 19 floods, 6 flash floods, 6 thunderstorm wind reports, 4 heavy rain events and 2 lightning strikes. They killed 2 people and injured 3, and the NWS estimated $17.2 million in property and crop damage. The strongest thunderstorm gust on record here was 67 mph, on December 24, 2025. December has had the most flash floods, 3 of 6. Of the 550 California cities on this site with a flash flood on record, 202 have had fewer than Half Moon Bay.
October 13, 2009: heavy rain event 7 miles from the centre of Half Moon Bay — 1 killed, 3 injured.
December 31, 2005: flood 5 miles from the centre of Half Moon Bay — 1 killed, $7.0 million damage.
December 31, 2005: flood 5 miles from the centre of Half Moon Bay — $5.0 million damage.
Source: NOAA NCEI Storm Events Database, events whose starting point is on record, 1996 to June 30, 2026. Damage is the NWS estimate in the dollars of the year, not insured losses, and NWS notes that some reports are unverified.
Flood insurance claims, disaster declarations and FEMA risk ratings
Flood insurance policyholders in Half Moon Bay's ZIP code 94019 have filed 15 claims with the National Flood Insurance Program since 1978, and were paid $95,000 for buildings and contents, in the dollars of each year. 67% of the claims carry the name of a storm or flood event; the rest have no event name. Of the 415 California cities on this site with 10 or more claims, 51 have fewer than Half Moon Bay.
San Mateo County, which includes Half Moon Bay, has been named in 24 federal disaster or emergency declarations since 1977, 17 of them major disasters (by incident: 7 floods, 7 severe storms, 3 fires, 2 biological emergencies). The latest major disaster declaration was Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides, on April 3, 2023. FEMA's National Risk Index gives San Mateo County a Relatively High rating for natural hazard risk overall; by hazard: Relatively High for inland flooding and coastal flooding; Relatively Moderate for lightning and heat waves; Relatively Low for tornadoes and strong wind; Very Low for hail. It models the county's expected loss from all 18 hazards it covers at $740.0 million a year, the 11th highest of 58 California counties; of the hazards above, the largest share, $212.3 million (29%), is from inland flooding.
Claims: FEMA, OpenFEMA Dataset FIMA NFIP Redacted Claims – v3, summed over ZIP codes; payments in the dollars of each year, not adjusted for inflation. Declarations: Disaster Declarations Summaries – v2, by county. Retrieved October 25, 2026. This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Risk ratings: FEMA, National Risk Index county table, December 2025 (v1.20), retrieved October 26, 2026; ratings compare counties nationwide, are meant for planning and are no substitute for a local risk assessment. This product uses the Federal Emergency Management Agency's National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
What counts as a pass, the distances and the sources: how this storm history is built.
Cities near Half Moon Bay
- El Granada, CA3 mi
- Moss Beach, CA5 mi
- Montara, CA6 mi
- Burlingame, CA8 mi
- San Mateo, CA9 mi
- Belmont, CA9 mi
- Millbrae, CA9 mi
- Pacifica, CA10 mi
- San Carlos, CA10 mi
- San Bruno, CA10 mi
- Foster City, CA11 mi
- Redwood City, CA11 mi
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