Walnut, California
36 topographic sheets cover this place, the earliest surveyed in 1894 and the latest in 1982. It stands in the East San Gabriel Valley census division. It lies in ZIP code area 91789. It stands on Lemon Creek. The Survey maps it on the San Dimas quadrangle. 28,430 people lived here at the 2020 count. It stands 561 feet above sea level.
Then and now
1894 to 1982The same ground, surveyed 88 years apart. Drag the handle to wipe between them. Both sheets are United States Geological Survey originals; neither has been altered.


Compare 1894 against another survey:
Population over time
2 figuresWalnut fell from 29,172 to 28,430 between 2010 and 2020. These are the recorded population figures Wikidata holds for this place, reached through the Geographic Names Information System number this page is keyed on rather than by name, so they belong to this place and not to another of the same name. Most are census counts, but not all are: an early figure may be a founding or settlement estimate, and an estimate published within five years of a census is left out. The change column is computed, and is left blank where more than 20 years separate a figure from the one before it, because a gap that long is not a change between two counts.
| Year | People | Change |
|---|---|---|
| 2010 | 29,172 | |
| 2020 | 28,430 | -742 (-3%) |
Topographic sheets covering this place
16 surveys from 36 printed sheetsMatched by testing this settlement's coordinate against the published boundary of every sheet in the United States Geological Survey's historical collection. Each opens the scanned sheet at the Survey.
- 1894 USGS Pomona quadrangle1:62500
- 1897 USGS Pomona quadrangle1:62500
- 1898 USGS Pomona quadrangle1:62500, 2 printings
- 1901 USGS Southern California Sheet No. 1 quadrangle1:250000, 6 printings
- 1904 USGS Pomona quadrangle1:62500, 7 printings
- 1904 USGS Southern California Sheet No. 1 quadrangle1:250000, 2 printings
- 1927 USGS Covina quadrangle1:24000, 3 printings
- 1953 USGS San Bernardino quadrangle1:250000, 2 printings
- 1954 USGS San Dimas quadrangle1:24000, 2 printings
- 1956 USGS San Bernardino quadrangle1:250000
- 1957 USGS San Bernardino quadrangle1:250000
- 1958 USGS San Bernardino quadrangle1:250000
- 1959 USGS San Bernardino quadrangle1:250000
- 1966 USGS San Bernardino quadrangle1:250000
- 1966 USGS San Dimas quadrangle1:24000, 4 printings
- 1982 USGS San Bernardino quadrangle1:100000
Fires near this place
376 since 2005Regional context, not property-specific evidence. The federal wildfire occurrence database lists 376 fires within 5 miles of Walnut between 2005 and 2020, burning about 434 acres in total. 1 started naturally. 48 were recorded as arson. Distance is straight-line from the map coordinates, so a fire counted here may appear on a neighbouring settlement's page as well.
| Reported cause | Fires |
|---|---|
| Missing data/not specified/undetermined | 221 |
| Arson/incendiarism | 48 |
| Smoking | 45 |
| Equipment and vehicle use | 26 |
| Misuse of fire by a minor | 22 |
| Debris and open burning | 11 |
| Power generation/transmission/distribution | 2 |
| Natural | 1 |
The most recent of them, most recent first, with the day each was reported and the service that recorded it.
| Date | Cause | Size | Reported by | Name on the report |
|---|---|---|---|---|
| 8 September 2009 | Misuse of fire by a minor | under an acre | California Department of Forestry & Fire Protection | not named |
| 5 September 2008 | Equipment and vehicle use | under an acre | California Department of Forestry & Fire Protection | not named |
| 5 September 2005 | Missing data/not specified/undetermined | under an acre | California Department of Forestry & Fire Protection | not named |
| 4 September 2008 | Smoking | under an acre | California Department of Forestry & Fire Protection | not named |
| 4 September 2006 | Missing data/not specified/undetermined | under an acre | California Department of Forestry & Fire Protection | not named |
| 4 September 2006 | Missing data/not specified/undetermined | under an acre | California Department of Forestry & Fire Protection | not named |
| 4 September 2006 | Debris and open burning | under an acre | California Department of Forestry & Fire Protection | not named |
| 29 September 2016 | Misuse of fire by a minor | under an acre | California Department of Forestry & Fire Protection | not named |
Settlements close enough to share some of these fires:
Mines and quarries near this place
3 within 5 milesRegional context, not property-specific evidence. The federal mineral resources record lists 3 workings within 5 miles of Walnut: 1 occurrence, 1 producer, 1 past producer. 1 still produces. What was taken out: Diatomite, Geothermal. Distance is straight-line from the map coordinates, so a quarry counted here may appear on a neighbouring settlement's page as well.
| Where | Site | Commodity | Status | Recorded |
|---|---|---|---|---|
| Alvardo Hot Springs | Geothermal | Occurrence | ||
| Featherstone Deposit | Diatomite | Producer | Sedimentary | |
| Featherstone Deposit | Diatomite | Past Producer |
Storms near this place
3 since 1998Regional context, not property-specific evidence. The National Weather Service names Walnut in 3 storm reports between 1998 and 2014: 1 flash flood, 1 tornado, 1 hail. No death or injury is recorded in these reports. Each account below is quoted exactly as the forecast office filed it, from the NOAA Storm Events Database, and each date opens the federal record of that event.
| When | Event | Place named | Harm | What the report says |
|---|---|---|---|---|
| March 2014 | Hail | Walnut | - | A severe thunderstorm moved across the community of Walnut. A trained weather spotter reported 1.50 inch hail from this storm. |
| December 2001 | Tornado (F0) | Walnut | - | In the community of Walnut, a weak tornado touched down in the early morning hours. Several homes sustained minor roof damage and about 30 trees were knocked down. No injuries were reported. |
| September 1998 | Flash Flood | Walnut | - | no account filed |
Nearest settlements
The eight closest, with where each one stands in the county. Distances are straight-line, computed from the Geographic Names Information System coordinates.
| Map | Place | Distance | Sheets |
|---|---|---|---|
| Woodside Village | 1.8 miles | 37 | |
| South San Jose Hills | 2.2 miles | 36 | |
| Marne | 2.4 miles | 36 | |
| Otterbein | 2.5 miles | 48 | |
| Diamond Bar | 3.0 miles | 36 | |
| Rowland | 3.6 miles | 36 | |
| Rowland Heights | 3.7 miles | 47 | |
| Spadra | 4.1 miles | 36 |
Elsewhere
Matched on this settlement's Geographic Names Information System number rather than its name, so it cannot be a different place of the same name in another state.
| Wikipedia article on Walnut | An encyclopaedic summary. Its text is share-alike, so it is linked here rather than copied. |
| Wikidata item Q850979 | The structured record the population and elevation above come from. Public domain (CC0). |
Provenance
This settlement is recorded in the Geographic Names Information System as feature 1652808. The sheet list is computed by point-in-boundary test against the United States Geological Survey's historical topographic inventory. Both are works of the United States government and carry no copyright under 17 U.S.C. 105.
Wildfire. Short, Karen C. 2022. Spatial wildfire occurrence data for the United States, 1992-2020 [FPA_FOD_20221014]. 6th Edition. Fort Collins, CO: Forest Service Research Data Archive. https://doi.org/10.2737/RDS-2013-0009.6 Collected with United States Government funding and usable without additional permissions or fees.
Mines and quarries. USGS Mineral Resources Data System (MRDS) https://mrdata.usgs.gov/mrds/ A work of the United States government, no copyright under 17 U.S.C. 105.
Storms. NOAA National Centers for Environmental Information, Storm Events Database https://www.ncei.noaa.gov/stormevents/ A work of the United States government, no copyright under 17 U.S.C. 105. Narratives are quoted verbatim from the National Weather Service report and are not edited or summarised.















