Round Mountain Weather Records (USR0000CROU)

Record envelope, standing records and threshold days for Round Mountain (USR0000CROU), California, United States, with 33 years of record.

Key Facts for Round Mountain

Round Mountain (USR0000CROU) is a weather station in California, United States at 41.43 latitude and -121.46 longitude, 1,603 m (5,258 ft) above sea level.
The station reports from 1991 to 2023, 33 years of record.
1,464 records set at Round Mountain still stand.
Records are tracked for tmax, tmin: an element needs 30 years of data to be eligible.
Round Mountain set a daily record high maximum temperature of 30.6 C (87.1 F) on 7 October 2026 (provisional).

Provisional Records

Records set in the last 60 days are provisional until they clear the revision window.

About the Station

Location: California, United States, 41.43 latitude, -121.46 longitude.
Elevation: 1,603 m (5,258 ft).
Period of record: 1991 to 2023, 33 years.
Eligible elements: tmax, tmin.

Daily Record Envelope and 2026

25 days at or beyond a record

The band shows the record high and record low for each calendar day at Round Mountain. The lines show the 2026 daily maximum and minimum. 25 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.

Daily record high and record low at Round Mountain, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	18.3 C (64.9 F)	-19.4 C (-2.9 F)	13.9 C (57.0 F)	-7.2 C (19.0 F)
Feb	20.0 C (68.0 F)	-17.8 C (0.0 F)	17.2 C (63.0 F)	-10.0 C (14.0 F)
Mar	26.7 C (80.1 F)	-12.2 C (10.0 F)	26.7 C (80.1 F)	-3.3 C (26.1 F)
Apr	26.7 C (80.1 F)	-11.1 C (12.0 F)	20.6 C (69.1 F)	-6.1 C (21.0 F)
May	31.7 C (89.1 F)	-6.1 C (21.0 F)	26.7 C (80.1 F)	-0.6 C (30.9 F)
Jun	38.3 C (100.9 F)	-4.4 C (24.1 F)	32.2 C (90.0 F)	2.2 C (36.0 F)
Jul	39.4 C (102.9 F)	2.2 C (36.0 F)	31.7 C (89.1 F)	6.1 C (43.0 F)
Aug	37.8 C (100.0 F)	0.0 C (32.0 F)	36.1 C (97.0 F)	8.3 C (46.9 F)
Sep	37.8 C (100.0 F)	-2.8 C (27.0 F)	30.6 C (87.1 F)	2.8 C (37.0 F)
Oct	31.7 C (89.1 F)	-10.0 C (14.0 F)	30.6 C (87.1 F)	0.6 C (33.1 F)
Nov	23.9 C (75.0 F)	-13.9 C (7.0 F)	n/a	n/a
Dec	17.2 C (63.0 F)	-20.6 C (-5.1 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Round Mountain still stand. 2008 holds the most, with 71.

Standing records at Round Mountain by the year they were set
Year set	Standing records
1991	36
1992	53
1993	40
1994	46
1995	49
1996	57
1997	25
1998	42
1999	43
2000	31
2001	41
2002	51
2003	45
2004	33
2005	46
2006	34
2007	39
2008	71
2009	36
2010	32
2011	33
2012	32
2013	46
2014	35
2015	51
2016	36
2017	47
2018	20
2019	29
2020	38
2021	56
2022	45
2023	35
2024	34
2025	45
2026	32

All-Time Record Progression

1 new records

1 all-time records were set at Round Mountain between 30 July 2022 and 30 July 2022. Each dot is a new record.

Period of Record Coverage

1991 to 2026

36 years of record at Round Mountain, 1991 to 2026. 7 years have data for under 90 percent of days and are left out of rankings: 1991, 1993, 1994, 1995, 1997, 2010, 2026.

Days with data per year at Round Mountain
Year	Days with data	Share of year	Complete
1991	290	79%	No
1992	362	99%	Yes
1993	238	65%	No
1994	318	87%	No
1995	323	88%	No
1996	360	98%	Yes
1997	314	86%	No
1998	339	93%	Yes
1999	345	95%	Yes
2000	366	100%	Yes
2001	364	100%	Yes
2002	364	100%	Yes
2003	365	100%	Yes
2004	365	100%	Yes
2005	365	100%	Yes
2006	365	100%	Yes
2007	359	98%	Yes
2008	363	99%	Yes
2009	364	100%	Yes
2010	314	86%	No
2011	364	100%	Yes
2012	365	100%	Yes
2013	330	90%	Yes
2014	364	100%	Yes
2015	365	100%	Yes
2016	364	99%	Yes
2017	362	99%	Yes
2018	365	100%	Yes
2019	364	100%	Yes
2020	365	100%	Yes
2021	364	100%	Yes
2022	364	100%	Yes
2023	365	100%	Yes
2024	366	100%	Yes
2025	364	100%	Yes
2026	283	78%	No

Latest Records

Latest records at Round Mountain
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
7 October 2026	Round Mountain, US	daily high max (Provisional)	30.6 C (87.1 F)	0.6 C (1.1 F)	29 years	11 of 100 (Routine)
6 October 2026	Round Mountain, US	daily high max (Tie, Provisional)	29.4 C (84.9 F)	tie	12 years	1 of 100 (Routine)
5 October 2026	Round Mountain, US	daily high min (Provisional)	15.6 C (60.1 F)	0.6 C (1.1 F)	35 years	14 of 100 (Routine)
5 October 2026	Round Mountain, US	daily high max (Provisional)	28.3 C (82.9 F)	0.5 C (0.9 F)	12 years	6 of 100 (Routine)
4 October 2026	Round Mountain, US	daily high max (Provisional)	30.0 C (86.0 F)	2.8 C (5.0 F)	35 years	17 of 100 (Routine)
4 October 2026	Round Mountain, US	daily high min (Provisional)	17.2 C (63.0 F)	2.2 C (4.0 F)	1 year	7 of 100 (Routine)
3 October 2026	Round Mountain, US	daily high min (Provisional)	15.0 C (59.0 F)	0.6 C (1.1 F)	32 years	13 of 100 (Routine)
2 October 2026	Round Mountain, US	daily high min (Provisional)	16.7 C (62.1 F)	1.7 C (3.1 F)	24 years	13 of 100 (Routine)
13 September 2026	Round Mountain, US	daily low min (Tie, Provisional)	2.8 C (37.0 F)	tie	33 years	3 of 100 (Routine)
6 September 2026	Round Mountain, US	daily low max (Provisional)	15.0 C (59.0 F)	1.1 C (2.0 F)	24 years	11 of 100 (Routine)
3 September 2026	Round Mountain, US	daily low max (Provisional)	8.3 C (46.9 F)	5.6 C (10.1 F)	25 years	19 of 100 (Routine)
2 September 2026	Round Mountain, US	daily low max (Provisional)	7.8 C (46.0 F)	1.6 C (2.9 F)	25 years	12 of 100 (Routine)
21 August 2026	Round Mountain, US	daily high min (Tie, Provisional)	17.2 C (63.0 F)	tie	31 years	3 of 100 (Routine)
8 August 2026	Round Mountain, US	daily high max (Tie)	35.0 C (95.0 F)	tie	24 years	2 of 100 (Routine)
7 August 2026	Round Mountain, US	daily high min	21.1 C (70.0 F)	1.7 C (3.1 F)	20 years	13 of 100 (Routine)
7 August 2026	Round Mountain, US	daily high max	36.1 C (97.0 F)	0.5 C (0.9 F)	24 years	11 of 100 (Routine)
5 August 2026	Round Mountain, US	daily high max (Tie)	34.4 C (93.9 F)	tie	28 years	2 of 100 (Routine)
4 August 2026	Round Mountain, US	daily high max (Tie)	34.4 C (93.9 F)	tie	28 years	2 of 100 (Routine)
29 June 2026	Round Mountain, US	daily low min	3.3 C (37.9 F)	1.1 C (2.0 F)	33 years	15 of 100 (Routine)
27 June 2026	Round Mountain, US	daily low min	4.4 C (39.9 F)	0.6 C (1.1 F)	29 years	12 of 100 (Routine)

Climate Trend

26 complete years, 1992 to 2025

One stripe for each of 26 complete years at Round Mountain, 1992 to 2025. Blue stripes are years cooler than the station's own mean of 9.8 C (49.6 F); red stripes are warmer. The coolest year was 2011, at 8.5 C (47.3 F), and the warmest was 2015, at 11.1 C (51.9 F). The strongest colour marks a difference of 1.3 C (2.3 F).

Annual mean temperature at Round Mountain as warming stripes, 1992 to 2025
Year	Annual mean temperature	Difference from the station mean
1992	10.1 C	+0.34 C
1996	9.6 C	-0.22 C
2000	9.3 C	-0.46 C
2001	9.4 C	-0.41 C
2002	9.6 C	-0.16 C
2003	9.4 C	-0.38 C
2004	9.4 C	-0.39 C
2005	9.2 C	-0.65 C
2006	9.0 C	-0.76 C
2007	9.3 C	-0.54 C
2008	9.1 C	-0.69 C
2009	9.3 C	-0.53 C
2011	8.5 C	-1.30 C
2012	9.6 C	-0.19 C
2014	11.0 C	+1.18 C
2015	11.1 C	+1.28 C
2016	10.0 C	+0.17 C
2017	10.0 C	+0.20 C
2018	10.2 C	+0.37 C
2019	9.3 C	-0.55 C
2020	10.8 C	+1.04 C
2021	10.9 C	+1.08 C
2022	10.4 C	+0.61 C
2023	9.5 C	-0.33 C
2024	10.3 C	+0.47 C
2025	10.6 C	+0.78 C

This station does not have enough complete years (30 are needed) to fit a temperature trend.

A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.

Extremes by Year

1991 to 2026

Yearly extremes at Round Mountain: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	39.4 C (102.9 F)	2022	36.1 C (97.0 F)	36
Coldest night (TNn)	-20.6 C (-5.1 F)	1998	-11.9 C (10.5 F)	36

Hottest day (TXx)

The hottest day of the year at Round Mountain, 1991 to 2026. The record is 39.4 C (102.9 F) in 2022, marked on the chart; the median year is 36.1 C (97.0 F).

Hottest day (TXx) at Round Mountain by year
Year	Hottest day (TXx)
1991	33.3 C (91.9 F)
1992	37.2 C (99.0 F)
1993	34.4 C (93.9 F)
1994	36.1 C (97.0 F)
1995	31.1 C (88.0 F)
1996	35.6 C (96.1 F)
1997	35.6 C (96.1 F)
1998	35.6 C (96.1 F)
1999	36.7 C (98.1 F)
2000	35.6 C (96.1 F)
2001	35.6 C (96.1 F)
2002	38.3 C (100.9 F)
2003	37.8 C (100.0 F)
2004	34.4 C (93.9 F)
2005	33.9 C (93.0 F)
2006	35.0 C (95.0 F)
2007	38.3 C (100.9 F)
2008	36.1 C (97.0 F)
2009	35.6 C (96.1 F)
2010	34.4 C (93.9 F)
2011	32.8 C (91.0 F)
2012	35.0 C (95.0 F)
2013	36.1 C (97.0 F)
2014	36.1 C (97.0 F)
2015	36.1 C (97.0 F)
2016	35.6 C (96.1 F)
2017	37.8 C (100.0 F)
2018	36.1 C (97.0 F)
2019	35.6 C (96.1 F)
2020	36.7 C (98.1 F)
2021	38.3 C (100.9 F)
2022	39.4 C (102.9 F)
2023	36.1 C (97.0 F)
2024	37.8 C (100.0 F)
2025	36.7 C (98.1 F)
2026	36.1 C (97.0 F)

Coldest night (TNn)

The coldest night of the year at Round Mountain, 1991 to 2026. The record is -20.6 C (-5.1 F) in 1998, marked on the chart; the median year is -11.9 C (10.5 F).

Coldest night (TNn) at Round Mountain by year
Year	Coldest night (TNn)
1991	-8.9 C (16.0 F)
1992	-9.4 C (15.1 F)
1993	-13.9 C (7.0 F)
1994	-10.6 C (12.9 F)
1995	-8.9 C (16.0 F)
1996	-12.8 C (9.0 F)
1997	-10.0 C (14.0 F)
1998	-20.6 C (-5.1 F)
1999	-10.6 C (12.9 F)
2000	-7.8 C (18.0 F)
2001	-10.6 C (12.9 F)
2002	-13.9 C (7.0 F)
2003	-9.4 C (15.1 F)
2004	-11.1 C (12.0 F)
2005	-8.9 C (16.0 F)
2006	-11.7 C (10.9 F)
2007	-14.4 C (6.1 F)
2008	-13.9 C (7.0 F)
2009	-15.0 C (5.0 F)
2010	-12.2 C (10.0 F)
2011	-17.8 C (0.0 F)
2012	-11.7 C (10.9 F)
2013	-18.9 C (-2.0 F)
2014	-13.9 C (7.0 F)
2015	-12.2 C (10.0 F)
2016	-13.3 C (8.1 F)
2017	-19.4 C (-2.9 F)
2018	-11.7 C (10.9 F)
2019	-12.2 C (10.0 F)
2020	-10.0 C (14.0 F)
2021	-10.0 C (14.0 F)
2022	-15.6 C (3.9 F)
2023	-14.4 C (6.1 F)
2024	-8.9 C (16.0 F)
2025	-12.8 C (9.0 F)
2026	-10.0 C (14.0 F)

Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.

Frost Dates and Growing Season

26 years with a frost

Across 26 years with a frost, the median last spring frost at Round Mountain falls on 4 June and the median first autumn frost on 11 October, which leaves a median of 130 days between them.

Fitted over all years, the growing season changes by +1.2 days per decade at this station.

Frost dates and growing season at Round Mountain
Measure	Median, all years	Earliest period	Recent period (1992 to 2025)	Recent against earliest	Fitted trend
Last spring frost	4 June	n/a	4 June	n/a	+1.9 days per decade
First autumn frost	11 October	n/a	11 October	n/a	+3.0 days per decade
Growing days	130 days	n/a	130 days	n/a	+1.2 days per decade

A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.

Download the Data

Data for Round Mountain standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Round Mountain threshold days by year: CSV or JSON. Field meanings are on the data page.

Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-13 (13 October 2026). Records are computed by this site and are not official.

Data as of 2026-10-13. Last revised 13 October 2026 (2026-10-13).