Rosso Weather Records (MR000001489)

Record envelope, standing records and threshold days for Rosso (MR000001489), Mauritania, with 74 years of record.

Key Facts for Rosso

Rosso (MR000001489) is a weather station in Mauritania at 16.50 latitude and -15.82 longitude, 5 m (16 ft) above sea level.
The station reports from 1945 to 2018, 74 years of record.
1,464 records set at Rosso still stand.
Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
Rosso tied a daily record low maximum temperature of 25.0 C (77.0 F) on 22 December 2017.

About the Station

Location: Mauritania, 16.50 latitude, -15.82 longitude.
Elevation: 5 m (16 ft).
Period of record: 1945 to 2018, 74 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 Rosso. 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 Rosso, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	40.5 C (104.9 F)	3.6 C (38.5 F)	n/a	n/a
Feb	44.2 C (111.6 F)	7.3 C (45.1 F)	n/a	n/a
Mar	45.3 C (113.5 F)	10.2 C (50.4 F)	n/a	n/a
Apr	45.6 C (114.1 F)	11.1 C (52.0 F)	n/a	n/a
May	46.6 C (115.9 F)	10.6 C (51.1 F)	n/a	n/a
Jun	47.5 C (117.5 F)	11.7 C (53.1 F)	n/a	n/a
Jul	47.0 C (116.6 F)	16.0 C (60.8 F)	n/a	n/a
Aug	44.8 C (112.6 F)	17.3 C (63.1 F)	n/a	n/a
Sep	43.7 C (110.7 F)	15.0 C (59.0 F)	n/a	n/a
Oct	45.0 C (113.0 F)	14.6 C (58.3 F)	n/a	n/a
Nov	43.6 C (110.5 F)	11.2 C (52.2 F)	n/a	n/a
Dec	41.3 C (106.3 F)	4.5 C (40.1 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Rosso still stand. 1947 holds the most, with 120.

Standing records at Rosso by the year they were set
Year set	Standing records
1945	20
1946	15
1947	120
1948	15
1949	32
1950	27
1951	16
1952	26
1953	23
1954	16
1955	28
1956	34
1957	33
1958	17
1959	14
1960	23
1961	11
1962	11
1963	27
1964	16
1965	27
1966	9
1967	20
1968	25
1969	23
1970	28
1971	13
1972	33
1973	24
1974	26
1975	34
1976	26
1977	15
1978	19
1979	20
1980	23
1981	16
1982	9
1983	22
1984	14
1985	12
1986	12
1987	30
1988	21
1989	31
1990	36
1991	12
1992	13
1993	17
1994	8
1995	18
1996	12
1997	8
1998	11
1999	1
2000	6
2001	2
2002	4
2003	3
2004	6
2005	15
2006	14
2007	7
2008	18
2009	21
2010	56
2011	27
2012	21
2013	13
2014	36
2015	6
2016	13
2017	4

All-Time Record Progression

5 new records

5 all-time records were set at Rosso between 2 June 1976 and 11 August 2005. Each dot is a new record.

When Rosso set new all-time records
Date	Kind	Detail
1976-06-02	Record high minimum temperature	Record high minimum temperature 34.5 C (94.1 F)
1978-09-30	Record high minimum temperature	Record high minimum temperature 35.5 C (95.9 F)
1989-06-05	Record high maximum temperature	Record high maximum temperature 47.5 C (117.5 F)
1998-12-11	Record daily precipitation	Record daily precipitation 106.9 mm (4.2 in)
2005-08-11	Record daily precipitation	Record daily precipitation 153.9 mm (6.1 in)

Wettest Day of Each Month

Aug: 153.9 mm (6.1 in)

The wettest day on record for each calendar month at Rosso. The most was 153.9 mm (6.1 in) on 11 August 2005.

Record daily precipitation for each month at Rosso
Month	Record daily precipitation (mm)	Date
Jan	7.7 mm (0.30 in)	19 January 1958
Feb	8.6 mm (0.34 in)	1 February 1965
Mar	1.2 mm (0.05 in)	20 March 1976
Apr	9.9 mm (0.39 in)	18 April 1988
May	13.0 mm (0.5 in)	30 May 1952
Jun	61.0 mm (2.4 in)	1 June 1949
Jul	115.1 mm (4.5 in)	3 July 2011
Aug	153.9 mm (6.1 in)	11 August 2005
Sep	89.9 mm (3.5 in)	27 September 1993
Oct	83.1 mm (3.3 in)	2 October 1996
Nov	18.1 mm (0.7 in)	3 November 1951
Dec	106.9 mm (4.2 in)	11 December 1998

Period of Record Coverage

1945 to 2018

74 years of record at Rosso, 1945 to 2018. 42 years have data for under 90 percent of days and are left out of rankings: 1946, 1948, 1962, 1966, 1981, 1982, 1983, 1984 and others.

Days with data per year at Rosso
Year	Days with data	Share of year	Complete
1945	364	100%	Yes
1946	275	75%	No
1947	354	97%	Yes
1948	308	84%	No
1949	353	97%	Yes
1950	346	95%	Yes
1951	361	99%	Yes
1952	365	100%	Yes
1953	365	100%	Yes
1954	365	100%	Yes
1955	363	99%	Yes
1956	363	99%	Yes
1957	364	100%	Yes
1958	357	98%	Yes
1959	364	100%	Yes
1960	366	100%	Yes
1961	365	100%	Yes
1962	315	86%	No
1963	365	100%	Yes
1964	366	100%	Yes
1965	365	100%	Yes
1966	253	69%	No
1967	365	100%	Yes
1968	366	100%	Yes
1969	365	100%	Yes
1970	365	100%	Yes
1971	365	100%	Yes
1972	366	100%	Yes
1973	365	100%	Yes
1974	365	100%	Yes
1975	343	94%	Yes
1976	366	100%	Yes
1977	364	100%	Yes
1978	365	100%	Yes
1979	365	100%	Yes
1980	365	100%	Yes
1981	255	70%	No
1982	179	49%	No
1983	207	57%	No
1984	223	61%	No
1985	211	58%	No
1986	228	62%	No
1987	247	68%	No
1988	292	80%	No
1989	264	72%	No
1990	260	71%	No
1991	200	55%	No
1992	202	55%	No
1993	246	67%	No
1994	257	70%	No
1995	165	45%	No
1996	133	36%	No
1997	58	16%	No
1998	88	24%	No
1999	43	12%	No
2000	113	31%	No
2001	30	8%	No
2002	37	10%	No
2003	33	9%	No
2004	47	13%	No
2005	67	18%	No
2006	64	18%	No
2007	47	13%	No
2008	187	51%	No
2009	243	67%	No
2010	276	76%	No
2011	296	81%	No
2012	205	56%	No
2013	302	83%	No
2014	292	80%	No
2015	249	68%	No
2016	243	66%	No
2017	192	53%	No
2018	3	1%	No

Latest Records

Latest records at Rosso
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
22 December 2017	Rosso, MR	daily low max (Tie)	25.0 C (77.0 F)	tie	56 years	6 of 100 (Routine)
28 October 2017	Rosso, MR	daily high max	41.5 C (106.7 F)	0.5 C (0.9 F)	36 years	18 of 100 (Routine)
10 October 2017	Rosso, MR	daily high max (Tie)	42.3 C (108.1 F)	tie	3 years	1 of 100 (Routine)
25 September 2017	Rosso, MR	daily rain	35.1 mm (1.4 in)	16.8 mm (0.7 in)	40 years	30 of 100 (Routine)
21 September 2017	Rosso, MR	daily high max	43.5 C (110.3 F)	1.1 C (2.0 F)	30 years	19 of 100 (Routine)
27 June 2017	Rosso, MR	daily low max	31.3 C (88.3 F)	2.4 C (4.3 F)	39 years	25 of 100 (Routine)
28 May 2017	Rosso, MR	daily low max	32.0 C (89.6 F)	0.4 C (0.7 F)	50 years	23 of 100 (Routine)
19 May 2017	Rosso, MR	daily low max (Tie)	34.0 C (93.2 F)	tie	72 years	7 of 100 (Routine)
16 December 2016	Rosso, MR	daily high max (Tie)	38.3 C (100.9 F)	tie	27 years	3 of 100 (Routine)
3 October 2016	Rosso, MR	daily high max	42.9 C (109.2 F)	0.7 C (1.3 F)	11 years	12 of 100 (Routine)
12 September 2016	Rosso, MR	daily low max	26.0 C (78.8 F)	0.8 C (1.4 F)	63 years	27 of 100 (Routine)
16 August 2016	Rosso, MR	daily low max	31.0 C (87.8 F)	0.2 C (0.4 F)	52 years	22 of 100 (Routine)
15 June 2016	Rosso, MR	daily low max	33.8 C (92.8 F)	0.2 C (0.4 F)	37 years	18 of 100 (Routine)
12 June 2016	Rosso, MR	daily low max	33.0 C (91.4 F)	0.3 C (0.5 F)	22 years	13 of 100 (Routine)
24 May 2016	Rosso, MR	daily low max	33.7 C (92.7 F)	1.3 C (2.3 F)	66 years	30 of 100 (Routine)
21 April 2016	Rosso, MR	daily high max	44.7 C (112.5 F)	1.2 C (2.2 F)	69 years	30 of 100 (Routine)
31 March 2016	Rosso, MR	daily low max	31.5 C (88.7 F)	0.1 C (0.2 F)	47 years	21 of 100 (Routine)
19 January 2016	Rosso, MR	daily high max	37.3 C (99.1 F)	1.6 C (2.9 F)	45 years	25 of 100 (Routine)
17 January 2016	Rosso, MR	daily high max	37.2 C (99.0 F)	0.4 C (0.7 F)	5 years	9 of 100 (Routine)
14 January 2016	Rosso, MR	daily high max	38.7 C (101.7 F)	3.0 C (5.4 F)	1 year	16 of 100 (Routine)

Climate Trend

31 complete years, 1945 to 1980

One stripe for each of 31 complete years at Rosso, 1945 to 1980. Blue stripes are years cooler than the station's own mean of 27.6 C (81.7 F); red stripes are warmer. The coolest year was 1947, at 26.5 C (79.7 F), and the warmest was 1979, at 28.7 C (83.6 F). The strongest colour marks a difference of 1.1 C (2.0 F).

Annual mean temperature at Rosso as warming stripes, 1945 to 1980
Year	Annual mean temperature	Difference from the station mean
1945	28.3 C	+0.70 C
1947	26.5 C	-1.09 C
1949	27.4 C	-0.18 C
1950	27.4 C	-0.19 C
1951	27.6 C	-0.03 C
1952	27.2 C	-0.45 C
1953	27.4 C	-0.22 C
1954	27.6 C	-0.06 C
1955	27.4 C	-0.22 C
1956	26.9 C	-0.68 C
1957	26.8 C	-0.78 C
1958	27.8 C	+0.21 C
1959	27.2 C	-0.43 C
1960	27.4 C	-0.25 C
1961	27.6 C	-0.02 C
1963	27.7 C	+0.06 C
1964	27.6 C	-0.02 C
1965	26.7 C	-0.89 C
1967	26.9 C	-0.69 C
1968	27.2 C	-0.44 C
1969	28.4 C	+0.83 C
1970	28.5 C	+0.86 C
1971	27.8 C	+0.17 C
1972	28.3 C	+0.64 C
1973	28.4 C	+0.78 C
1974	27.1 C	-0.53 C
1976	27.6 C	+0.03 C
1977	28.6 C	+1.02 C
1978	28.2 C	+0.61 C
1979	28.7 C	+1.05 C
1980	27.9 C	+0.26 C

The annual mean temperature here has risen by 0.3 C (0.1 to 0.5) per decade over 1945 to 1980. In Fahrenheit: 0.5 F (0.2 to 0.8) per decade. The slope is a straight line fitted to 31 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Rosso
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	0.3 C (0.1 to 0.5) per decade	0.5 F (0.2 to 0.8) per decade	1945 to 1980	31	Rise
Mean daily maximum	0.2 C (-0.1 to 0.4) per decade	0.3 F (-0.2 to 0.7) per decade	1945 to 1980	31	Not clearly different from zero
Mean daily minimum	0.4 C (0.2 to 0.6) per decade	0.7 F (0.3 to 1.2) per decade	1945 to 1980	31	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

1945 to 2018

Yearly extremes at Rosso: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	47.5 C (117.5 F)	1989	45.5 C (113.8 F)	74
Coldest night (TNn)	3.6 C (38.5 F)	1948	10.6 C (51.1 F)	73
Wettest day (Rx1day)	153.9 mm (6.1 in)	2005	45.5 mm (1.8 in)	70
Wettest five days (Rx5day)	242.3 mm (9.5 in)	1947	73.0 mm (2.9 in)	38
Longest dry spell (CDD)	228 days	1977	86 days	68

Hottest day (TXx)

The hottest day of the year at Rosso, 1945 to 2018. The record is 47.5 C (117.5 F) in 1989, marked on the chart; the median year is 45.5 C (113.8 F).

Hottest day (TXx) at Rosso by year
Year	Hottest day (TXx)
1945	45.8 C (114.4 F)
1946	45.6 C (114.1 F)
1947	47.0 C (116.6 F)
1948	45.6 C (114.1 F)
1949	45.9 C (114.6 F)
1950	45.5 C (113.9 F)
1951	45.2 C (113.4 F)
1952	46.0 C (114.8 F)
1953	46.0 C (114.8 F)
1954	45.7 C (114.3 F)
1955	44.2 C (111.6 F)
1956	44.4 C (111.9 F)
1957	45.6 C (114.1 F)
1958	44.5 C (112.1 F)
1959	46.0 C (114.8 F)
1960	44.7 C (112.5 F)
1961	46.8 C (116.2 F)
1962	44.8 C (112.6 F)
1963	44.8 C (112.6 F)
1964	45.0 C (113.0 F)
1965	45.3 C (113.5 F)
1966	45.0 C (113.0 F)
1967	45.0 C (113.0 F)
1968	44.6 C (112.3 F)
1969	45.6 C (114.1 F)
1970	46.2 C (115.2 F)
1971	45.4 C (113.7 F)
1972	45.0 C (113.0 F)
1973	46.5 C (115.7 F)
1974	45.0 C (113.0 F)
1975	46.3 C (115.3 F)
1976	45.6 C (114.1 F)
1977	45.2 C (113.4 F)
1978	45.0 C (113.0 F)
1979	45.6 C (114.1 F)
1980	45.3 C (113.5 F)
1981	47.0 C (116.6 F)
1982	44.7 C (112.5 F)
1983	43.0 C (109.4 F)
1984	45.8 C (114.4 F)
1985	45.2 C (113.4 F)
1986	46.4 C (115.5 F)
1987	45.4 C (113.7 F)
1988	46.0 C (114.8 F)
1989	47.5 C (117.5 F)
1990	46.0 C (114.8 F)
1991	47.3 C (117.1 F)
1992	45.0 C (113.0 F)
1993	44.5 C (112.1 F)
1994	46.5 C (115.7 F)
1995	46.6 C (115.9 F)
1996	47.0 C (116.6 F)
1997	44.6 C (112.3 F)
1998	45.2 C (113.4 F)
1999	41.0 C (105.8 F)
2000	46.0 C (114.8 F)
2001	43.3 C (109.9 F)
2002	42.6 C (108.7 F)
2003	43.0 C (109.4 F)
2004	47.0 C (116.6 F)
2005	43.6 C (110.5 F)
2006	46.5 C (115.7 F)
2007	41.5 C (106.7 F)
2008	44.0 C (111.2 F)
2009	45.7 C (114.3 F)
2010	45.8 C (114.4 F)
2011	45.9 C (114.6 F)
2012	45.0 C (113.0 F)
2013	45.3 C (113.5 F)
2014	45.7 C (114.3 F)
2015	46.2 C (115.2 F)
2016	44.7 C (112.5 F)
2017	45.5 C (113.9 F)
2018	33.3 C (91.9 F)

Coldest night (TNn)

The coldest night of the year at Rosso, 1945 to 2018. The record is 3.6 C (38.5 F) in 1948, marked on the chart; the median year is 10.6 C (51.1 F).

Coldest night (TNn) at Rosso by year
Year	Coldest night (TNn)
1945	10.8 C (51.4 F)
1946	7.6 C (45.7 F)
1947	5.5 C (41.9 F)
1948	3.6 C (38.5 F)
1949	10.4 C (50.7 F)
1950	9.2 C (48.6 F)
1951	9.7 C (49.5 F)
1952	8.5 C (47.3 F)
1953	8.9 C (48.0 F)
1954	8.4 C (47.1 F)
1955	8.6 C (47.5 F)
1956	7.0 C (44.6 F)
1957	9.9 C (49.8 F)
1958	10.0 C (50.0 F)
1959	9.0 C (48.2 F)
1960	7.0 C (44.6 F)
1961	9.4 C (48.9 F)
1962	9.2 C (48.6 F)
1963	6.6 C (43.9 F)
1964	9.2 C (48.6 F)
1965	6.8 C (44.2 F)
1966	10.0 C (50.0 F)
1967	8.8 C (47.8 F)
1968	8.8 C (47.8 F)
1969	12.6 C (54.7 F)
1970	9.0 C (48.2 F)
1971	10.0 C (50.0 F)
1972	11.0 C (51.8 F)
1973	10.5 C (50.9 F)
1974	9.2 C (48.6 F)
1975	10.0 C (50.0 F)
1976	10.0 C (50.0 F)
1977	10.9 C (51.6 F)
1978	12.2 C (54.0 F)
1979	12.5 C (54.5 F)
1980	4.5 C (40.1 F)
1981	12.0 C (53.6 F)
1982	10.7 C (51.3 F)
1983	12.5 C (54.5 F)
1984	10.4 C (50.7 F)
1985	12.0 C (53.6 F)
1986	10.6 C (51.1 F)
1987	11.3 C (52.3 F)
1988	11.0 C (51.8 F)
1989	9.7 C (49.5 F)
1990	11.2 C (52.2 F)
1991	11.7 C (53.1 F)
1992	13.5 C (56.3 F)
1993	11.5 C (52.7 F)
1994	8.3 C (46.9 F)
1995	8.5 C (47.3 F)
1996	14.4 C (57.9 F)
1997	14.0 C (57.2 F)
1998	10.4 C (50.7 F)
1999	7.3 C (45.1 F)
2000	13.0 C (55.4 F)
2001	14.0 C (57.2 F)
2002	15.7 C (60.3 F)
2003	11.7 C (53.1 F)
2004	12.5 C (54.5 F)
2005	16.2 C (61.2 F)
2006	14.0 C (57.2 F)
2007	12.6 C (54.7 F)
2008	13.6 C (56.5 F)
2009	11.3 C (52.3 F)
2010	13.5 C (56.3 F)
2011	13.6 C (56.5 F)
2012	11.2 C (52.2 F)
2013	11.0 C (51.8 F)
2014	13.0 C (55.4 F)
2015	23.9 C (75.0 F)
2016	24.0 C (75.2 F)
2017	24.7 C (76.5 F)
2018	n/a

Wettest day (Rx1day)

The wettest day of the year at Rosso, 1945 to 2018. The record is 153.9 mm (6.1 in) in 2005, marked on the chart; the median year is 45.5 mm (1.8 in).

Wettest day (Rx1day) at Rosso by year
Year	Wettest day (Rx1day)
1945	35.0 mm (1.4 in)
1946	19.2 mm (0.8 in)
1947	100.4 mm (4.0 in)
1948	39.7 mm (1.6 in)
1949	61.0 mm (2.4 in)
1950	32.9 mm (1.3 in)
1951	32.6 mm (1.3 in)
1952	51.3 mm (2.0 in)
1953	56.5 mm (2.2 in)
1954	46.5 mm (1.8 in)
1955	37.6 mm (1.5 in)
1956	57.1 mm (2.2 in)
1957	81.8 mm (3.2 in)
1958	42.1 mm (1.7 in)
1959	46.0 mm (1.8 in)
1960	66.8 mm (2.6 in)
1961	59.4 mm (2.3 in)
1962	47.5 mm (1.9 in)
1963	35.0 mm (1.4 in)
1964	54.6 mm (2.1 in)
1965	55.4 mm (2.2 in)
1966	n/a
1967	55.5 mm (2.2 in)
1968	24.2 mm (1.0 in)
1969	53.0 mm (2.1 in)
1970	29.4 mm (1.2 in)
1971	38.9 mm (1.5 in)
1972	17.2 mm (0.7 in)
1973	41.3 mm (1.6 in)
1974	32.4 mm (1.3 in)
1975	48.7 mm (1.9 in)
1976	50.1 mm (2.0 in)
1977	35.6 mm (1.4 in)
1978	79.8 mm (3.1 in)
1979	85.3 mm (3.4 in)
1980	48.9 mm (1.9 in)
1981	70.1 mm (2.8 in)
1982	65.0 mm (2.6 in)
1983	2.0 mm (0.08 in)
1984	48.0 mm (1.9 in)
1985	49.0 mm (1.9 in)
1986	7.1 mm (0.28 in)
1987	32.0 mm (1.3 in)
1988	41.9 mm (1.6 in)
1989	36.1 mm (1.4 in)
1990	41.9 mm (1.6 in)
1991	24.9 mm (1.0 in)
1992	55.9 mm (2.2 in)
1993	89.9 mm (3.5 in)
1994	45.0 mm (1.8 in)
1995	6.1 mm (0.24 in)
1996	83.1 mm (3.3 in)
1997	33.0 mm (1.3 in)
1998	106.9 mm (4.2 in)
1999	15.0 mm (0.6 in)
2000	65.0 mm (2.6 in)
2001	23.9 mm (0.9 in)
2002	1.0 mm (0.04 in)
2003	23.1 mm (0.9 in)
2004	1.0 mm (0.04 in)
2005	153.9 mm (6.1 in)
2006	n/a
2007	n/a
2008	26.9 mm (1.1 in)
2009	71.9 mm (2.8 in)
2010	55.9 mm (2.2 in)
2011	115.1 mm (4.5 in)
2012	13.0 mm (0.5 in)
2013	88.9 mm (3.5 in)
2014	24.9 mm (1.0 in)
2015	47.0 mm (1.9 in)
2016	7.1 mm (0.28 in)
2017	35.1 mm (1.4 in)
2018	n/a

Wettest five days (Rx5day)

The wettest five days of the year at Rosso, 1945 to 2018. The record is 242.3 mm (9.5 in) in 1947, marked on the chart; the median year is 73.0 mm (2.9 in).

Wettest five days (Rx5day) at Rosso by year
Year	Wettest five days (Rx5day)
1945	52.7 mm (2.1 in)
1946	22.8 mm (0.9 in)
1947	242.3 mm (9.5 in)
1948	73.7 mm (2.9 in)
1949	82.0 mm (3.2 in)
1950	64.9 mm (2.6 in)
1951	76.3 mm (3.0 in)
1952	73.2 mm (2.9 in)
1953	93.5 mm (3.7 in)
1954	59.5 mm (2.3 in)
1955	76.7 mm (3.0 in)
1956	111.8 mm (4.4 in)
1957	95.2 mm (3.7 in)
1958	100.4 mm (4.0 in)
1959	46.5 mm (1.8 in)
1960	72.8 mm (2.9 in)
1961	94.3 mm (3.7 in)
1962	83.6 mm (3.3 in)
1963	58.9 mm (2.3 in)
1964	112.6 mm (4.4 in)
1965	68.8 mm (2.7 in)
1966	n/a
1967	59.1 mm (2.3 in)
1968	34.0 mm (1.3 in)
1969	72.8 mm (2.9 in)
1970	41.3 mm (1.6 in)
1971	39.9 mm (1.6 in)
1972	17.9 mm (0.7 in)
1973	57.8 mm (2.3 in)
1974	48.4 mm (1.9 in)
1975	80.5 mm (3.2 in)
1976	85.0 mm (3.3 in)
1977	43.6 mm (1.7 in)
1978	88.2 mm (3.5 in)
1979	100.4 mm (4.0 in)
1980	70.3 mm (2.8 in)
1981	111.3 mm (4.4 in)
1982	n/a
1983	n/a
1984	n/a
1985	n/a
1986	n/a
1987	n/a
1988	n/a
1989	57.1 mm (2.2 in)
1990	n/a
1991	n/a
1992	n/a
1993	n/a
1994	n/a
1995	n/a
1996	n/a
1997	n/a
1998	n/a
1999	n/a
2000	n/a
2001	n/a
2002	n/a
2003	n/a
2004	n/a
2005	n/a
2006	n/a
2007	n/a
2008	n/a
2009	n/a
2010	n/a
2011	n/a
2012	n/a
2013	129.8 mm (5.1 in)
2014	n/a
2015	n/a
2016	n/a
2017	n/a
2018	n/a

Longest dry spell (CDD)

The longest dry spell of the year at Rosso, 1945 to 2018. The record is 228 days in 1977, marked on the chart; the median year is 86 days.

Longest dry spell (CDD) at Rosso by year
Year	Longest dry spell (CDD)
1945	170 days
1946	100 days
1947	203 days
1948	191 days
1949	150 days
1950	160 days
1951	87 days
1952	150 days
1953	121 days
1954	107 days
1955	139 days
1956	193 days
1957	110 days
1958	148 days
1959	169 days
1960	196 days
1961	171 days
1962	174 days
1963	169 days
1964	193 days
1965	138 days
1966	n/a
1967	159 days
1968	92 days
1969	182 days
1970	197 days
1971	181 days
1972	158 days
1973	178 days
1974	206 days
1975	96 days
1976	85 days
1977	228 days
1978	124 days
1979	134 days
1980	131 days
1981	12 days
1982	1 day
1983	3 days
1984	2 days
1985	1 day
1986	4 days
1987	2 days
1988	1 day
1989	2 days
1990	2 days
1991	2 days
1992	2 days
1993	2 days
1994	1 day
1995	2 days
1996	1 day
1997	1 day
1998	1 day
1999	3 days
2000	2 days
2001	1 day
2002	1 day
2003	1 day
2004	1 day
2005	1 day
2006	n/a
2007	n/a
2008	2 days
2009	1 day
2010	1 day
2011	1 day
2012	2 days
2013	1 day
2014	1 day
2015	2 days
2016	n/a
2017	n/a
2018	n/a

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.

Rainfall Return Levels

34 years, 1945 to 1980

A day with at least 46.5 mm (1.8 in) of rain is expected about once in 2 years. A day with at least 106.1 mm (4.2 in) of rain is expected about once in 100 years.

Rainfall return levels at Rosso: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	46.5 mm (1.8 in)
5 years	62.6 mm (2.5 in)
10 years	73.2 mm (2.9 in)
25 years	86.6 mm (3.4 in)
50 years	96.4 mm (3.8 in)	Longer than the 34 years of record
100 years	106.1 mm (4.2 in)	Longer than the 34 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, 34 years of values from 1945 to 1980.

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: 100.4 mm (4.0 in) in 1947; 85.3 mm (3.4 in) in 1979; 81.8 mm (3.2 in) in 1957.

Download the Data

Data for Rosso standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Rosso 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 2026-10-17 (17 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).