NHC HURDAT2 · SPC Tornado Database
Hurricanes and Tornadoes That Hit Diamond Bar, 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 Diamond Bar, California since records began in 1851. Since 1950, 41 tornadoes have touched down within 25 miles, 0 of them rated EF3 or stronger.
- Hurricanes
- 0
- Tropical storms
- 0
- Tornadoes
- 41
- 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 Diamond Bar
The highest rating among the 41 tornadoes within 25 miles is F2, reached 2 times; the most recent, on November 9, 1982, came within 16 miles. Of the 41, one had a path within 5 miles of the city centre, and 10 have come since 2000. March has had the most tornadoes, 11. The most recent tornado was on March 13, 2025. Diamond Bar has more tornadoes within 25 miles than 89% of the 705 California cities on this site. Hail has been reported within 10 miles 3 times since 2005, with stones up to 1.5 inches (ping pong ball size). Of the 705 California cities, 44% have more hail reports within 10 miles than Diamond Bar.
Compare Diamond Bar's storm record with another city →
Tornadoes within 25 miles of Diamond Bar
By decade
- 2020s4
- 2010s1
- 2000s5
- 1990s15
- 1980s7
- 1970s4
- 1960s4
- 1950s1
| Date | Rating | Distance | Path | Killed / injured |
|---|---|---|---|---|
| Nov 9, 1982 | F2 | 16 mi | 10 mi | 0 / 0 |
| Nov 7, 1966 | F2 | 21 mi | 10.3 mi | 0 / 10 |
| Mar 22, 2023 | EF1 | 17 mi | 0.47 mi | 0 / 1 |
| Jan 19, 2010 | EF1 | 23 mi | 4.62 mi | 0 / 0 |
| Nov 11, 1997 | F1 | 22 mi | 0.2 mi | 0 / 0 |
| Jan 14, 1993 | F1 | 12 mi | 1 mi | 0 / 0 |
| Dec 7, 1992 | F1 | 13 mi | 0.1 mi | 0 / 0 |
| Dec 7, 1992 | F1 | 20 mi | 0.1 mi | 0 / 0 |
| Mar 20, 1992 | F1 | 22 mi | 0.2 mi | 0 / 0 |
| Mar 27, 1991 | F1 | 22 mi | 3 mi | 0 / 0 |
| Mar 16, 1986 | F1 | 13 mi | 1.2 mi | 0 / 0 |
| Mar 29, 1982 | F1 | 17 mi | 2 mi | 0 / 0 |
The strongest 12 of 41, by rating and then by deaths. Ratings before February 2007 are on the original Fujita scale.
Hail in Diamond Bar
The Storm Prediction Center has 3 hail reports within 10 miles of Diamond Bar since 2005. Of these, one was 1 inch across or larger, and none reached 2 inches. The largest, 1.5 inches (ping pong ball size), fell on March 1, 2014. The most recent report is from March 20, 2019.
Source: NOAA Storm Prediction Center severe weather reports, data through 2025.
Weather by month in Diamond Bar
The nearest NOAA station with 1991–2020 climate normals is Pomona/Fairplex, CA, 6 miles northeast of Diamond Bar at 999 feet. August is the warmest, with an average high of 92°F and low of 63°F; December is the coolest, at 67°F and 42°F. Highs reach 90°F on about 71 days a year, almost all from April to October. Lows fall below freezing on about 3 nights a year. That 14.5 inches is more than at 98 of the 226 California stations used on this site (43%). Rowland Heights, 5 miles west, has its own station (Anaheim, CA): 13.6 inches a year, 0.9 less than here, and an August average high of 89°F against 92°F.
| Month | High °F | Low °F | Precip. in | Days ≥ 0.1" |
|---|---|---|---|---|
| Jan | 68 | 43 | 2.9 | 4 |
| Feb | 67 | 45 | 4.2 | 5 |
| Mar | 72 | 47 | 2.1 | 3 |
| Apr | 76 | 50 | 1.0 | 1 |
| May | 78 | 54 | 0.2 | 0 |
| Jun | 84 | 57 | 0.1 | 0 |
| Jul | 90 | 62 | 0.0 | 0 |
| Aug | 92 | 63 | 0.0 | 0 |
| Sep | 89 | 60 | 0.0 | 0 |
| Oct | 81 | 54 | 1.0 | 2 |
| Nov | 74 | 47 | 0.7 | 1 |
| Dec | 67 | 42 | 2.3 | 4 |
| Year | 78 | 52 | 14.5 | 21 |
Averages for 1991–2020 at Pomona/Fairplex, CA (999 ft), from NOAA NCEI U.S. Climate Normals. 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 Diamond Bar
Since 1996, the National Weather Service has logged 30 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Diamond Bar: 11 flash floods, 10 thunderstorm wind reports, 5 floods and 4 heavy rain events. They killed 1 person and injured 0, and the NWS estimated $711,000 in property and crop damage. The strongest thunderstorm gust on record here was 100 mph, on April 18, 2000. February has had the most flash floods, 4 of 11. Of the 550 California cities on this site with a flash flood on record, 304 have had fewer than Diamond Bar.
December 19, 2010: flood 8 miles from the centre of Diamond Bar — 1 killed.
January 9, 2005: flash flood 8 miles from the centre of Diamond Bar — $500,000 damage.
February 21, 2005: flash flood 7 miles from the centre of Diamond Bar — $100,000 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
Los Angeles County, which includes Diamond Bar, has been named in 88 federal disaster or emergency declarations since 1969, 35 of them major disasters (by incident: 61 fires, 10 floods, 8 severe storms, 3 earthquakes). The latest major disaster declaration was Wildfires and Straight-Line Winds, on January 8, 2025. FEMA's National Risk Index gives Los Angeles County a Very High rating for natural hazard risk overall; by hazard: Very High for inland flooding and lightning; Relatively High for tornadoes, coastal flooding and heat waves; Relatively Moderate for hail and strong wind. It models the county's expected loss from all 18 hazards it covers at $7.60 billion a year, the highest of 58 California counties; of the hazards above, the largest share, $2.81 billion (37%), 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.