Riito Weather Records (MXN00026076)

Record envelope, standing records and threshold days for Riito (MXN00026076), Mexico, with 62 years of record.

Key Facts for Riito

Riito (MXN00026076) is a weather station in Mexico at 32.13 latitude and -114.90 longitude, 16 m (52 ft) above sea level.
The station reports from 1949 to 2010, 62 years of record.
1,464 records set at Riito still stand.
Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
Riito set a daily record high maximum temperature of 47.8 C (118.0 F) on 31 August 2010.

About the Station

Location: Mexico, 32.13 latitude, -114.90 longitude.
Elevation: 16 m (52 ft).
Period of record: 1949 to 2010, 62 years.
Eligible elements: tmax, tmin, prcp.

Daily Record Envelope and 2026

0 days at or beyond a record

The band shows the record high and record low for each calendar day at Riito. The lines show the 2026 daily maximum and minimum. 0 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.

Daily record high and record low at Riito, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	30.6 C (87.1 F)	-6.7 C (19.9 F)	n/a	n/a
Feb	35.6 C (96.1 F)	-5.6 C (21.9 F)	n/a	n/a
Mar	38.9 C (102.0 F)	-3.9 C (25.0 F)	n/a	n/a
Apr	42.8 C (109.0 F)	1.7 C (35.1 F)	n/a	n/a
May	48.9 C (120.0 F)	4.4 C (39.9 F)	n/a	n/a
Jun	50.0 C (122.0 F)	3.9 C (39.0 F)	n/a	n/a
Jul	56.1 C (133.0 F)	4.4 C (39.9 F)	n/a	n/a
Aug	49.4 C (120.9 F)	4.4 C (39.9 F)	n/a	n/a
Sep	47.8 C (118.0 F)	0.6 C (33.1 F)	n/a	n/a
Oct	50.0 C (122.0 F)	-1.1 C (30.0 F)	n/a	n/a
Nov	47.8 C (118.0 F)	-2.8 C (27.0 F)	n/a	n/a
Dec	40.6 C (105.1 F)	-6.1 C (21.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Riito still stand. 1981 holds the most, with 147.

Standing records at Riito by the year they were set
Year set	Standing records
1949	17
1950	24
1951	17
1952	14
1953	22
1954	15
1955	26
1956	25
1957	61
1958	70
1959	16
1960	20
1961	14
1962	29
1963	26
1964	27
1965	18
1966	19
1967	19
1968	22
1969	24
1970	11
1971	33
1972	26
1973	15
1974	8
1975	23
1976	9
1977	13
1978	12
1979	12
1980	10
1981	147
1982	19
1983	7
1984	9
1985	20
1986	16
1987	20
1988	11
1989	12
1990	30
1991	20
1992	21
1993	27
1994	19
1995	29
1996	18
1997	26
1998	16
1999	3
2000	11
2001	30
2002	46
2003	25
2004	20
2005	38
2006	22
2007	49
2008	20
2009	26
2010	10

Wettest Day of Each Month

Sep: 79.8 mm (3.1 in)

The wettest day on record for each calendar month at Riito. The most was 79.8 mm (3.1 in) on 1 September 1967.

Record daily precipitation for each month at Riito
Month	Record daily precipitation (mm)	Date
Jan	28.2 mm (1.1 in)	16 January 1979
Feb	30.0 mm (1.2 in)	2 February 1983
Mar	46.0 mm (1.8 in)	6 March 2001
Apr	18.8 mm (0.7 in)	21 April 1957
May	29.0 mm (1.1 in)	10 May 1957
Jun	15.0 mm (0.6 in)	10 June 1981
Jul	19.8 mm (0.8 in)	5 July 1968
Aug	48.8 mm (1.9 in)	23 August 1955
Sep	79.8 mm (3.1 in)	1 September 1967
Oct	68.3 mm (2.7 in)	6 October 1972
Nov	45.0 mm (1.8 in)	9 November 1969
Dec	25.9 mm (1.0 in)	24 December 1959

Period of Record Coverage

1949 to 2010

62 years of record at Riito, 1949 to 2010. 12 years have data for under 90 percent of days and are left out of rankings: 1949, 1954, 1963, 1981, 1989, 1993, 1994, 1998 and others.

Days with data per year at Riito
Year	Days with data	Share of year	Complete
1949	195	53%	No
1950	365	100%	Yes
1951	365	100%	Yes
1952	366	100%	Yes
1953	365	100%	Yes
1954	324	89%	No
1955	365	100%	Yes
1956	362	99%	Yes
1957	360	99%	Yes
1958	359	98%	Yes
1959	365	100%	Yes
1960	366	100%	Yes
1961	365	100%	Yes
1962	362	99%	Yes
1963	292	80%	No
1964	363	99%	Yes
1965	362	99%	Yes
1966	330	90%	Yes
1967	364	100%	Yes
1968	366	100%	Yes
1969	364	100%	Yes
1970	365	100%	Yes
1971	364	100%	Yes
1972	366	100%	Yes
1973	365	100%	Yes
1974	363	99%	Yes
1975	363	99%	Yes
1976	364	99%	Yes
1977	364	100%	Yes
1978	358	98%	Yes
1979	346	95%	Yes
1980	350	96%	Yes
1981	282	77%	No
1982	365	100%	Yes
1983	364	100%	Yes
1984	366	100%	Yes
1985	359	98%	Yes
1986	365	100%	Yes
1987	354	97%	Yes
1988	366	100%	Yes
1989	302	83%	No
1990	336	92%	Yes
1991	364	100%	Yes
1992	360	98%	Yes
1993	166	45%	No
1994	326	89%	No
1995	361	99%	Yes
1996	360	98%	Yes
1997	337	92%	Yes
1998	326	89%	No
1999	212	58%	No
2000	364	99%	Yes
2001	363	99%	Yes
2002	298	82%	No
2003	295	81%	No
2004	363	99%	Yes
2005	357	98%	Yes
2006	360	99%	Yes
2007	363	99%	Yes
2008	325	89%	No
2009	361	99%	Yes
2010	334	92%	Yes

Latest Records

Latest records at Riito
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
31 August 2010	Riito, MX	daily high max	47.8 C (118.0 F)	1.7 C (3.1 F)	60 years	28 of 100 (Routine)
29 August 2010	Riito, MX	daily low min	15.6 C (60.1 F)	0.5 C (0.9 F)	56 years	24 of 100 (Routine)
27 August 2010	Riito, MX	daily high max	47.8 C (118.0 F)	1.1 C (2.0 F)	40 years	21 of 100 (Routine)
24 July 2010	Riito, MX	daily high max (Tie)	45.6 C (114.1 F)	tie	20 years	3 of 100 (Routine)
23 July 2010	Riito, MX	all-time high min (Tie)	32.8 C (91.0 F)	tie	38 years	9 of 100 (Routine)
16 July 2010	Riito, MX	daily high min (Tie)	28.9 C (84.0 F)	tie	55 years	5 of 100 (Routine)
3 July 2010	Riito, MX	daily high min	28.9 C (84.0 F)	1.7 C (3.1 F)	56 years	27 of 100 (Routine)
24 May 2010	Riito, MX	daily low max	22.8 C (73.0 F)	3.3 C (5.9 F)	28 years	21 of 100 (Routine)
23 April 2010	Riito, MX	daily low max	20.0 C (68.0 F)	2.8 C (5.0 F)	29 years	20 of 100 (Routine)
22 April 2010	Riito, MX	daily low max (Tie)	20.6 C (69.1 F)	tie	40 years	4 of 100 (Routine)
10 March 2010	Riito, MX	daily low max	16.7 C (62.1 F)	2.2 C (4.0 F)	43 years	22 of 100 (Routine)
8 March 2010	Riito, MX	daily low max	15.6 C (60.1 F)	1.1 C (2.0 F)	57 years	25 of 100 (Routine)
20 February 2010	Riito, MX	daily high max	32.8 C (91.0 F)	2.2 C (4.0 F)	38 years	22 of 100 (Routine)
2 January 2010	Riito, MX	daily high max (Tie)	26.7 C (80.1 F)	tie	14 years	2 of 100 (Routine)
1 January 2010	Riito, MX	daily high max (Tie)	28.9 C (84.0 F)	tie	14 years	2 of 100 (Routine)
20 December 2009	Riito, MX	daily high min (Tie)	10.0 C (50.0 F)	tie	56 years	5 of 100 (Routine)
19 December 2009	Riito, MX	daily high min	15.0 C (59.0 F)	3.3 C (5.9 F)	18 years	20 of 100 (Routine)
29 November 2009	Riito, MX	daily high min	16.7 C (62.1 F)	1.7 C (3.1 F)	14 years	14 of 100 (Routine)
29 November 2009	Riito, MX	daily high max	36.7 C (98.1 F)	1.1 C (2.0 F)	3 years	8 of 100 (Routine)
28 November 2009	Riito, MX	daily high max	35.6 C (96.1 F)	3.9 C (7.0 F)	3 years	14 of 100 (Routine)

Climate Trend

46 complete years, 1950 to 2009

One stripe for each of 46 complete years at Riito, 1950 to 2009. Blue stripes are years cooler than the station's own mean of 21.8 C (71.2 F); red stripes are warmer. The coolest year was 1982, at 20.0 C (68.0 F), and the warmest was 2005, at 25.2 C (77.4 F). The strongest colour marks a difference of 3.5 C (6.3 F).

Annual mean temperature at Riito as warming stripes, 1950 to 2009
Year	Annual mean temperature	Difference from the station mean
1950	21.9 C	+0.11 C
1951	21.5 C	-0.29 C
1952	21.7 C	-0.07 C
1953	21.4 C	-0.39 C
1955	21.0 C	-0.80 C
1956	21.3 C	-0.46 C
1957	23.5 C	+1.72 C
1958	23.4 C	+1.58 C
1959	21.9 C	+0.09 C
1960	21.3 C	-0.46 C
1961	20.9 C	-0.86 C
1962	21.3 C	-0.53 C
1964	20.6 C	-1.16 C
1965	21.1 C	-0.72 C
1967	20.8 C	-0.97 C
1968	20.7 C	-1.11 C
1969	20.6 C	-1.14 C
1970	20.4 C	-1.40 C
1971	20.4 C	-1.38 C
1972	21.1 C	-0.68 C
1973	20.3 C	-1.44 C
1974	21.1 C	-0.67 C
1975	20.2 C	-1.55 C
1976	20.9 C	-0.91 C
1977	21.6 C	-0.19 C
1978	21.6 C	-0.22 C
1979	21.1 C	-0.70 C
1980	21.7 C	-0.09 C
1982	20.0 C	-1.77 C
1983	21.0 C	-0.83 C
1984	20.8 C	-0.94 C
1985	20.8 C	-0.98 C
1986	21.4 C	-0.41 C
1987	21.4 C	-0.43 C
1988	21.9 C	+0.10 C
1991	21.9 C	+0.12 C
1992	22.2 C	+0.41 C
1995	23.8 C	+1.97 C
1996	23.9 C	+2.08 C
2000	23.6 C	+1.80 C
2001	24.5 C	+2.70 C
2004	23.1 C	+1.35 C
2005	25.2 C	+3.42 C
2006	24.1 C	+2.30 C
2007	23.9 C	+2.07 C
2009	23.7 C	+1.89 C

The annual mean temperature here has risen by 0.4 C (0.2 to 0.6) per decade over 1950 to 2009. In Fahrenheit: 0.8 F (0.4 to 1.1) per decade. The slope is a straight line fitted to 46 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Riito
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	0.4 C (0.2 to 0.6) per decade	0.8 F (0.4 to 1.1) per decade	1950 to 2009	46	Rise
Mean daily maximum	0.30 C (0.04 to 0.56) per decade	0.5 F (0.1 to 1.0) per decade	1950 to 2009	46	Rise
Mean daily minimum	0.6 C (0.4 to 0.7) per decade	1.0 F (0.7 to 1.3) per decade	1950 to 2009	46	Rise

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

1949 to 2010

Yearly extremes at Riito: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	56.1 C (133.0 F)	1958	46.7 C (116.1 F)	62
Coldest night (TNn)	-6.7 C (19.9 F)	1950	-2.5 C (27.5 F)	62
Wettest day (Rx1day)	79.8 mm (3.1 in)	1967	14.1 mm (0.6 in)	62
Wettest five days (Rx5day)	133.3 mm (5.2 in)	1972	16.3 mm (0.6 in)	62
Longest dry spell (CDD)	334 days	2010	163 days	62

Hottest day (TXx)

The hottest day of the year at Riito, 1949 to 2010. The record is 56.1 C (133.0 F) in 1958, marked on the chart; the median year is 46.7 C (116.1 F).

Hottest day (TXx) at Riito by year
Year	Hottest day (TXx)
1949	46.7 C (116.1 F)
1950	46.7 C (116.1 F)
1951	46.7 C (116.1 F)
1952	47.2 C (117.0 F)
1953	47.2 C (117.0 F)
1954	46.7 C (116.1 F)
1955	47.2 C (117.0 F)
1956	46.7 C (116.1 F)
1957	48.3 C (118.9 F)
1958	56.1 C (133.0 F)
1959	46.7 C (116.1 F)
1960	45.6 C (114.1 F)
1961	47.8 C (118.0 F)
1962	46.7 C (116.1 F)
1963	45.0 C (113.0 F)
1964	46.7 C (116.1 F)
1965	48.9 C (120.0 F)
1966	47.8 C (118.0 F)
1967	45.0 C (113.0 F)
1968	45.0 C (113.0 F)
1969	46.7 C (116.1 F)
1970	47.8 C (118.0 F)
1971	46.7 C (116.1 F)
1972	46.7 C (116.1 F)
1973	47.8 C (118.0 F)
1974	46.7 C (116.1 F)
1975	45.6 C (114.1 F)
1976	46.7 C (116.1 F)
1977	46.7 C (116.1 F)
1978	46.7 C (116.1 F)
1979	46.7 C (116.1 F)
1980	46.7 C (116.1 F)
1981	29.4 C (84.9 F)
1982	45.0 C (113.0 F)
1983	41.7 C (107.1 F)
1984	43.9 C (111.0 F)
1985	48.9 C (120.0 F)
1986	45.0 C (113.0 F)
1987	47.8 C (118.0 F)
1988	45.6 C (114.1 F)
1989	45.6 C (114.1 F)
1990	45.6 C (114.1 F)
1991	45.0 C (113.0 F)
1992	42.8 C (109.0 F)
1993	48.9 C (120.0 F)
1994	45.6 C (114.1 F)
1995	50.0 C (122.0 F)
1996	46.7 C (116.1 F)
1997	47.8 C (118.0 F)
1998	47.8 C (118.0 F)
1999	42.8 C (109.0 F)
2000	47.8 C (118.0 F)
2001	46.7 C (116.1 F)
2002	46.7 C (116.1 F)
2003	50.0 C (122.0 F)
2004	47.8 C (118.0 F)
2005	48.9 C (120.0 F)
2006	47.8 C (118.0 F)
2007	48.9 C (120.0 F)
2008	48.9 C (120.0 F)
2009	48.9 C (120.0 F)
2010	47.8 C (118.0 F)

Coldest night (TNn)

The coldest night of the year at Riito, 1949 to 2010. The record is -6.7 C (19.9 F) in 1950, marked on the chart; the median year is -2.5 C (27.5 F).

Coldest night (TNn) at Riito by year
Year	Coldest night (TNn)
1949	-5.6 C (21.9 F)
1950	-6.7 C (19.9 F)
1951	-4.4 C (24.1 F)
1952	-5.0 C (23.0 F)
1953	-5.6 C (21.9 F)
1954	-5.0 C (23.0 F)
1955	-5.6 C (21.9 F)
1956	-3.9 C (25.0 F)
1957	-2.8 C (27.0 F)
1958	-1.7 C (28.9 F)
1959	-1.1 C (30.0 F)
1960	-4.4 C (24.1 F)
1961	-2.8 C (27.0 F)
1962	-5.0 C (23.0 F)
1963	-6.1 C (21.0 F)
1964	-5.6 C (21.9 F)
1965	-3.3 C (26.1 F)
1966	-5.0 C (23.0 F)
1967	-3.3 C (26.1 F)
1968	-5.0 C (23.0 F)
1969	-3.3 C (26.1 F)
1970	-3.3 C (26.1 F)
1971	-6.1 C (21.0 F)
1972	-5.0 C (23.0 F)
1973	-4.4 C (24.1 F)
1974	-3.3 C (26.1 F)
1975	-3.3 C (26.1 F)
1976	-6.1 C (21.0 F)
1977	-2.2 C (28.0 F)
1978	-5.0 C (23.0 F)
1979	-3.3 C (26.1 F)
1980	0.0 C (32.0 F)
1981	0.0 C (32.0 F)
1982	0.0 C (32.0 F)
1983	0.6 C (33.1 F)
1984	0.6 C (33.1 F)
1985	0.0 C (32.0 F)
1986	0.0 C (32.0 F)
1987	-4.4 C (24.1 F)
1988	-6.1 C (21.0 F)
1989	1.7 C (35.1 F)
1990	-3.3 C (26.1 F)
1991	0.6 C (33.1 F)
1992	0.6 C (33.1 F)
1993	0.6 C (33.1 F)
1994	1.7 C (35.1 F)
1995	0.6 C (33.1 F)
1996	1.7 C (35.1 F)
1997	1.7 C (35.1 F)
1998	0.6 C (33.1 F)
1999	1.7 C (35.1 F)
2000	1.7 C (35.1 F)
2001	2.8 C (37.0 F)
2002	1.7 C (35.1 F)
2003	2.8 C (37.0 F)
2004	1.7 C (35.1 F)
2005	2.8 C (37.0 F)
2006	1.7 C (35.1 F)
2007	0.6 C (33.1 F)
2008	1.7 C (35.1 F)
2009	0.6 C (33.1 F)
2010	1.7 C (35.1 F)

Wettest day (Rx1day)

The wettest day of the year at Riito, 1949 to 2010. The record is 79.8 mm (3.1 in) in 1967, marked on the chart; the median year is 14.1 mm (0.6 in).

Wettest day (Rx1day) at Riito by year
Year	Wettest day (Rx1day)
1949	6.9 mm (0.27 in)
1950	11.4 mm (0.4 in)
1951	18.3 mm (0.7 in)
1952	10.7 mm (0.4 in)
1953	8.9 mm (0.35 in)
1954	2.5 mm (0.10 in)
1955	48.8 mm (1.9 in)
1956	0.5 mm (0.02 in)
1957	29.0 mm (1.1 in)
1958	10.9 mm (0.4 in)
1959	25.9 mm (1.0 in)
1960	14.2 mm (0.6 in)
1961	10.2 mm (0.4 in)
1962	14.0 mm (0.6 in)
1963	14.0 mm (0.6 in)
1964	9.9 mm (0.39 in)
1965	10.2 mm (0.4 in)
1966	5.8 mm (0.23 in)
1967	79.8 mm (3.1 in)
1968	19.8 mm (0.8 in)
1969	45.0 mm (1.8 in)
1970	11.7 mm (0.5 in)
1971	28.7 mm (1.1 in)
1972	68.3 mm (2.7 in)
1973	7.9 mm (0.31 in)
1974	57.7 mm (2.3 in)
1975	14.0 mm (0.6 in)
1976	35.3 mm (1.4 in)
1977	17.0 mm (0.7 in)
1978	16.8 mm (0.7 in)
1979	28.2 mm (1.1 in)
1980	20.8 mm (0.8 in)
1981	15.0 mm (0.6 in)
1982	23.4 mm (0.9 in)
1983	30.0 mm (1.2 in)
1984	20.8 mm (0.8 in)
1985	8.9 mm (0.35 in)
1986	16.8 mm (0.7 in)
1987	11.9 mm (0.5 in)
1988	3.8 mm (0.15 in)
1989	1.3 mm (0.05 in)
1990	1.3 mm (0.05 in)
1991	17.8 mm (0.7 in)
1992	4.8 mm (0.19 in)
1993	2.8 mm (0.11 in)
1994	18.8 mm (0.7 in)
1995	16.8 mm (0.7 in)
1996	0.0 mm (0.00 in)
1997	8.9 mm (0.35 in)
1998	15.0 mm (0.6 in)
1999	9.9 mm (0.39 in)
2000	49.8 mm (2.0 in)
2001	46.0 mm (1.8 in)
2002	1.8 mm (0.07 in)
2003	17.8 mm (0.7 in)
2004	22.9 mm (0.9 in)
2005	10.9 mm (0.4 in)
2006	7.9 mm (0.31 in)
2007	34.8 mm (1.4 in)
2008	30.0 mm (1.2 in)
2009	5.8 mm (0.23 in)
2010	0.0 mm (0.00 in)

Wettest five days (Rx5day)

The wettest five days of the year at Riito, 1949 to 2010. The record is 133.3 mm (5.2 in) in 1972, marked on the chart; the median year is 16.3 mm (0.6 in).

Wettest five days (Rx5day) at Riito by year
Year	Wettest five days (Rx5day)
1949	9.4 mm (0.37 in)
1950	15.5 mm (0.6 in)
1951	35.1 mm (1.4 in)
1952	11.0 mm (0.4 in)
1953	9.2 mm (0.36 in)
1954	2.5 mm (0.10 in)
1955	48.8 mm (1.9 in)
1956	0.5 mm (0.02 in)
1957	33.8 mm (1.3 in)
1958	10.9 mm (0.4 in)
1959	46.5 mm (1.8 in)
1960	15.0 mm (0.6 in)
1961	18.4 mm (0.7 in)
1962	15.8 mm (0.6 in)
1963	18.1 mm (0.7 in)
1964	13.7 mm (0.5 in)
1965	10.2 mm (0.4 in)
1966	5.8 mm (0.23 in)
1967	95.5 mm (3.8 in)
1968	20.6 mm (0.8 in)
1969	45.0 mm (1.8 in)
1970	14.0 mm (0.6 in)
1971	28.7 mm (1.1 in)
1972	133.3 mm (5.2 in)
1973	11.5 mm (0.5 in)
1974	57.7 mm (2.3 in)
1975	14.0 mm (0.6 in)
1976	35.3 mm (1.4 in)
1977	23.1 mm (0.9 in)
1978	17.6 mm (0.7 in)
1979	28.2 mm (1.1 in)
1980	27.4 mm (1.1 in)
1981	54.6 mm (2.1 in)
1982	33.3 mm (1.3 in)
1983	39.7 mm (1.6 in)
1984	23.4 mm (0.9 in)
1985	11.7 mm (0.5 in)
1986	16.8 mm (0.7 in)
1987	15.2 mm (0.6 in)
1988	5.6 mm (0.22 in)
1989	1.3 mm (0.05 in)
1990	2.1 mm (0.08 in)
1991	17.8 mm (0.7 in)
1992	4.8 mm (0.19 in)
1993	5.6 mm (0.22 in)
1994	47.5 mm (1.9 in)
1995	16.8 mm (0.7 in)
1996	0.0 mm (0.00 in)
1997	11.7 mm (0.5 in)
1998	15.0 mm (0.6 in)
1999	9.9 mm (0.39 in)
2000	49.8 mm (2.0 in)
2001	46.0 mm (1.8 in)
2002	1.8 mm (0.07 in)
2003	17.8 mm (0.7 in)
2004	23.7 mm (0.9 in)
2005	10.9 mm (0.4 in)
2006	7.9 mm (0.31 in)
2007	34.8 mm (1.4 in)
2008	30.0 mm (1.2 in)
2009	5.8 mm (0.23 in)
2010	0.0 mm (0.00 in)

Longest dry spell (CDD)

The longest dry spell of the year at Riito, 1949 to 2010. The record is 334 days in 2010, marked on the chart; the median year is 163 days.

Longest dry spell (CDD) at Riito by year
Year	Longest dry spell (CDD)
1949	160 days
1950	129 days
1951	129 days
1952	106 days
1953	305 days
1954	115 days
1955	188 days
1956	245 days
1957	98 days
1958	154 days
1959	93 days
1960	229 days
1961	321 days
1962	241 days
1963	216 days
1964	158 days
1965	121 days
1966	215 days
1967	156 days
1968	179 days
1969	105 days
1970	208 days
1971	92 days
1972	157 days
1973	145 days
1974	201 days
1975	173 days
1976	100 days
1977	153 days
1978	114 days
1979	97 days
1980	81 days
1981	92 days
1982	178 days
1983	166 days
1984	194 days
1985	224 days
1986	156 days
1987	175 days
1988	131 days
1989	214 days
1990	249 days
1991	217 days
1992	143 days
1993	74 days
1994	213 days
1995	153 days
1996	154 days
1997	169 days
1998	30 days
1999	92 days
2000	231 days
2001	156 days
2002	241 days
2003	168 days
2004	201 days
2005	142 days
2006	168 days
2007	239 days
2008	240 days
2009	330 days
2010	334 days

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

28 years with a frost

Across 28 years with a frost, the median last spring frost at Riito falls on 24 February and the median first autumn frost on 29 November, which leaves a median of 287 days between them.

Fitted over all years, the growing season changes by +13.2 days per decade at this station.

Frost dates and growing season at Riito
Measure	Median, all years	Earliest period	Recent period (1950 to 1987)	Recent against earliest	Fitted trend
Last spring frost	24 February	n/a	24 February	n/a	-9.0 days per decade
First autumn frost	29 November	n/a	29 November	n/a	+4.2 days per decade
Growing days	287 days	n/a	287 days	n/a	+13.2 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.

Rainfall Return Levels

54 years, 1950 to 2010

A day with at least 15.6 mm (0.6 in) of rain is expected about once in 2 years. A day with at least 89.7 mm (3.5 in) of rain is expected about once in 100 years.

Rainfall return levels at Riito: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	15.6 mm (0.6 in)
5 years	29.7 mm (1.2 in)
10 years	41.0 mm (1.6 in)
25 years	57.9 mm (2.3 in)
50 years	72.8 mm (2.9 in)
100 years	89.7 mm (3.5 in)	Longer than the 54 years of record

The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 54 years of values from 1950 to 2010.

A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.

The largest wettest-day totals in the fit: 79.8 mm (3.1 in) in 1967; 68.3 mm (2.7 in) in 1972; 57.7 mm (2.3 in) in 1974.

Station Changes

2 suspected

2 changes were suspected in the annual mean temperature of Riito, at 1959 and 1995. Each is measured against neighbouring stations.

Relative to 5 neighbouring stations, the station's annual mean temperature from 1959 ran 0.6 C (1.2 F) lower than in the years before (possible change).
Relative to 5 neighbouring stations, the station's annual mean temperature from 1995 ran 1.2 C (2.2 F) higher than in the years before (likely change).

Suspected changes in the annual mean temperature at Riito, against neighbouring stations
Year	Shift (C)	Shift (F)	Strength	Neighbours
1959	-0.6	-1.2	possible	5
1995	+1.2	+2.2	likely	5

Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.

Download the Data

Data for Riito standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Riito 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 2026-10-16 (16 October 2026). Records are computed by this site and are not official.

Data as of 2025-12-31. Last revised 31 December 2025 (2025-12-31).