Rio Piedras Weather Records (RQC00668301)

Record envelope, standing records and threshold days for Rio Piedras (RQC00668301), PR, Puerto Rico [United States], with 31 years of record.

Key Facts for Rio Piedras

Rio Piedras (RQC00668301) is a weather station in PR, Puerto Rico [United States] at 18.40 latitude and -66.07 longitude, 30 m (98 ft) above sea level.
The station reports from 1931 to 1961, 31 years of record.
1,464 records set at Rio Piedras still stand.
Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.

About the Station

Location: PR, Puerto Rico [United States], 18.40 latitude, -66.07 longitude.
Elevation: 30 m (98 ft).
Period of record: 1931 to 1961, 31 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 Rio Piedras. 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 Rio Piedras, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	35.0 C (95.0 F)	13.3 C (55.9 F)	n/a	n/a
Feb	32.8 C (91.0 F)	11.1 C (52.0 F)	n/a	n/a
Mar	34.4 C (93.9 F)	13.9 C (57.0 F)	n/a	n/a
Apr	33.9 C (93.0 F)	15.0 C (59.0 F)	n/a	n/a
May	34.4 C (93.9 F)	16.1 C (61.0 F)	n/a	n/a
Jun	35.0 C (95.0 F)	15.0 C (59.0 F)	n/a	n/a
Jul	36.7 C (98.1 F)	16.7 C (62.1 F)	n/a	n/a
Aug	35.6 C (96.1 F)	17.2 C (63.0 F)	n/a	n/a
Sep	35.6 C (96.1 F)	15.6 C (60.1 F)	n/a	n/a
Oct	35.0 C (95.0 F)	16.7 C (62.1 F)	n/a	n/a
Nov	35.0 C (95.0 F)	15.0 C (59.0 F)	n/a	n/a
Dec	33.3 C (91.9 F)	12.8 C (55.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Rio Piedras still stand. 1944 holds the most, with 141.

Standing records at Rio Piedras by the year they were set
Year set	Standing records
1931	89
1932	64
1933	102
1934	48
1935	70
1936	59
1937	65
1939	26
1940	46
1941	53
1942	127
1943	118
1944	141
1945	30
1946	31
1947	25
1948	33
1949	24
1950	31
1951	30
1952	26
1953	18
1954	22
1955	24
1956	32
1957	17
1958	33
1959	21
1960	35
1961	24

Wettest Day of Each Month

Jan: 183.6 mm (7.2 in)

The wettest day on record for each calendar month at Rio Piedras. The most was 183.6 mm (7.2 in) on 6 January 1943.

Record daily precipitation for each month at Rio Piedras
Month	Record daily precipitation (mm)	Date
Jan	183.6 mm (7.2 in)	6 January 1943
Feb	124.5 mm (4.9 in)	3 February 1950
Mar	125.2 mm (4.9 in)	30 March 1958
Apr	147.3 mm (5.8 in)	18 April 1956
May	119.9 mm (4.7 in)	23 May 1941
Jun	106.7 mm (4.2 in)	16 June 1956
Jul	139.2 mm (5.5 in)	1 July 1950
Aug	127.0 mm (5.0 in)	14 August 1944
Sep	156.2 mm (6.1 in)	27 September 1932
Oct	77.5 mm (3.1 in)	6 October 1959
Nov	150.6 mm (5.9 in)	12 November 1961
Dec	127.0 mm (5.0 in)	5 December 1947

Period of Record Coverage

1931 to 1961

30 years of record at Rio Piedras, 1931 to 1961. 4 years have data for under 90 percent of days and are left out of rankings: 1931, 1932, 1945, 1951.

Days with data per year at Rio Piedras
Year	Days with data	Share of year	Complete
1931	319	87%	No
1932	302	83%	No
1933	343	94%	Yes
1934	363	99%	Yes
1935	364	100%	Yes
1936	363	99%	Yes
1937	362	99%	Yes
1939	365	100%	Yes
1940	366	100%	Yes
1941	329	90%	Yes
1942	358	98%	Yes
1943	363	99%	Yes
1944	336	92%	Yes
1945	275	75%	No
1946	357	98%	Yes
1947	360	99%	Yes
1948	366	100%	Yes
1949	357	98%	Yes
1950	361	99%	Yes
1951	268	73%	No
1952	364	99%	Yes
1953	363	99%	Yes
1954	365	100%	Yes
1955	365	100%	Yes
1956	365	100%	Yes
1957	363	99%	Yes
1958	365	100%	Yes
1959	365	100%	Yes
1960	361	99%	Yes
1961	361	99%	Yes

Latest Records

No records were set at this station in the latest data.

Climate Trend

25 complete years, 1931 to 1961

One stripe for each of 25 complete years at Rio Piedras, 1931 to 1961. Blue stripes are years cooler than the station's own mean of 25.2 C (77.3 F); red stripes are warmer. The coolest year was 1943, at 24.7 C (76.4 F), and the warmest was 1960, at 25.8 C (78.4 F). The strongest colour marks a difference of 0.7 C (1.3 F).

Annual mean temperature at Rio Piedras as warming stripes, 1931 to 1961
Year	Annual mean temperature	Difference from the station mean
1931	24.9 C	-0.28 C
1933	25.0 C	-0.15 C
1934	25.4 C	+0.21 C
1935	25.5 C	+0.30 C
1936	24.9 C	-0.31 C
1937	24.8 C	-0.37 C
1939	25.2 C	+0.02 C
1940	25.1 C	-0.05 C
1942	25.3 C	+0.16 C
1943	24.7 C	-0.50 C
1946	25.4 C	+0.27 C
1947	25.6 C	+0.46 C
1948	25.4 C	+0.21 C
1949	25.0 C	-0.13 C
1950	24.9 C	-0.24 C
1952	25.2 C	+0.04 C
1953	25.1 C	-0.09 C
1954	24.7 C	-0.46 C
1955	24.8 C	-0.36 C
1956	24.7 C	-0.46 C
1957	25.3 C	+0.10 C
1958	25.7 C	+0.48 C
1959	25.4 C	+0.20 C
1960	25.8 C	+0.62 C
1961	25.5 C	+0.30 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

1931 to 1961

Yearly extremes at Rio Piedras: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	36.7 C (98.1 F)	1942	33.9 C (93.0 F)	30
Coldest night (TNn)	11.1 C (52.0 F)	1942	15.0 C (59.0 F)	30
Wettest day (Rx1day)	183.6 mm (7.2 in)	1943	100.9 mm (4.0 in)	30
Wettest five days (Rx5day)	277.6 mm (10.9 in)	1958	152.5 mm (6.0 in)	30
Longest dry spell (CDD)	22 days	1942	15 days	30

Hottest day (TXx)

The hottest day of the year at Rio Piedras, 1931 to 1961. The record is 36.7 C (98.1 F) in 1942, marked on the chart; the median year is 33.9 C (93.0 F).

Hottest day (TXx) at Rio Piedras by year
Year	Hottest day (TXx)
1931	32.8 C (91.0 F)
1932	33.3 C (91.9 F)
1933	35.0 C (95.0 F)
1934	35.0 C (95.0 F)
1935	35.6 C (96.1 F)
1936	32.2 C (90.0 F)
1937	32.8 C (91.0 F)
1939	33.3 C (91.9 F)
1940	33.9 C (93.0 F)
1941	33.9 C (93.0 F)
1942	36.7 C (98.1 F)
1943	33.3 C (91.9 F)
1944	33.3 C (91.9 F)
1945	33.9 C (93.0 F)
1946	33.9 C (93.0 F)
1947	34.4 C (93.9 F)
1948	34.4 C (93.9 F)
1949	35.0 C (95.0 F)
1950	34.4 C (93.9 F)
1951	35.6 C (96.1 F)
1952	34.4 C (93.9 F)
1953	33.9 C (93.0 F)
1954	32.8 C (91.0 F)
1955	33.3 C (91.9 F)
1956	33.9 C (93.0 F)
1957	33.3 C (91.9 F)
1958	34.4 C (93.9 F)
1959	35.0 C (95.0 F)
1960	35.0 C (95.0 F)
1961	33.3 C (91.9 F)

Coldest night (TNn)

The coldest night of the year at Rio Piedras, 1931 to 1961. The record is 11.1 C (52.0 F) in 1942, marked on the chart; the median year is 15.0 C (59.0 F).

Coldest night (TNn) at Rio Piedras by year
Year	Coldest night (TNn)
1931	15.0 C (59.0 F)
1932	13.9 C (57.0 F)
1933	15.6 C (60.1 F)
1934	14.4 C (57.9 F)
1935	15.0 C (59.0 F)
1936	15.6 C (60.1 F)
1937	15.0 C (59.0 F)
1939	15.0 C (59.0 F)
1940	14.4 C (57.9 F)
1941	15.0 C (59.0 F)
1942	11.1 C (52.0 F)
1943	13.9 C (57.0 F)
1944	12.2 C (54.0 F)
1945	12.8 C (55.0 F)
1946	15.0 C (59.0 F)
1947	14.4 C (57.9 F)
1948	15.0 C (59.0 F)
1949	14.4 C (57.9 F)
1950	14.4 C (57.9 F)
1951	13.3 C (55.9 F)
1952	15.0 C (59.0 F)
1953	15.0 C (59.0 F)
1954	14.4 C (57.9 F)
1955	13.9 C (57.0 F)
1956	15.0 C (59.0 F)
1957	15.6 C (60.1 F)
1958	15.0 C (59.0 F)
1959	15.0 C (59.0 F)
1960	15.6 C (60.1 F)
1961	16.1 C (61.0 F)

Wettest day (Rx1day)

The wettest day of the year at Rio Piedras, 1931 to 1961. The record is 183.6 mm (7.2 in) in 1943, marked on the chart; the median year is 100.9 mm (4.0 in).

Wettest day (Rx1day) at Rio Piedras by year
Year	Wettest day (Rx1day)
1931	95.3 mm (3.8 in)
1932	156.2 mm (6.1 in)
1933	97.3 mm (3.8 in)
1934	108.0 mm (4.3 in)
1935	61.0 mm (2.4 in)
1936	78.7 mm (3.1 in)
1937	95.0 mm (3.7 in)
1939	104.6 mm (4.1 in)
1940	132.1 mm (5.2 in)
1941	119.9 mm (4.7 in)
1942	51.3 mm (2.0 in)
1943	183.6 mm (7.2 in)
1944	127.0 mm (5.0 in)
1945	111.0 mm (4.4 in)
1946	77.5 mm (3.1 in)
1947	140.7 mm (5.5 in)
1948	118.6 mm (4.7 in)
1949	80.3 mm (3.2 in)
1950	139.2 mm (5.5 in)
1951	104.6 mm (4.1 in)
1952	69.1 mm (2.7 in)
1953	56.1 mm (2.2 in)
1954	70.1 mm (2.8 in)
1955	72.9 mm (2.9 in)
1956	147.3 mm (5.8 in)
1957	58.2 mm (2.3 in)
1958	125.2 mm (4.9 in)
1959	77.5 mm (3.1 in)
1960	70.9 mm (2.8 in)
1961	150.6 mm (5.9 in)

Wettest five days (Rx5day)

The wettest five days of the year at Rio Piedras, 1931 to 1961. The record is 277.6 mm (10.9 in) in 1958, marked on the chart; the median year is 152.5 mm (6.0 in).

Wettest five days (Rx5day) at Rio Piedras by year
Year	Wettest five days (Rx5day)
1931	150.0 mm (5.9 in)
1932	203.4 mm (8.0 in)
1933	143.2 mm (5.6 in)
1934	154.9 mm (6.1 in)
1935	117.7 mm (4.6 in)
1936	160.3 mm (6.3 in)
1937	267.2 mm (10.5 in)
1939	146.5 mm (5.8 in)
1940	176.2 mm (6.9 in)
1941	203.5 mm (8.0 in)
1942	112.2 mm (4.4 in)
1943	238.7 mm (9.4 in)
1944	263.1 mm (10.4 in)
1945	188.5 mm (7.4 in)
1946	106.9 mm (4.2 in)
1947	220.4 mm (8.7 in)
1948	135.1 mm (5.3 in)
1949	139.8 mm (5.5 in)
1950	211.3 mm (8.3 in)
1951	181.9 mm (7.2 in)
1952	117.1 mm (4.6 in)
1953	133.2 mm (5.2 in)
1954	129.3 mm (5.1 in)
1955	112.5 mm (4.4 in)
1956	235.6 mm (9.3 in)
1957	77.9 mm (3.1 in)
1958	277.6 mm (10.9 in)
1959	136.1 mm (5.4 in)
1960	115.1 mm (4.5 in)
1961	251.8 mm (9.9 in)

Longest dry spell (CDD)

The longest dry spell of the year at Rio Piedras, 1931 to 1961. The record is 22 days in 1942, marked on the chart; the median year is 15 days.

Longest dry spell (CDD) at Rio Piedras by year
Year	Longest dry spell (CDD)
1931	12 days
1932	21 days
1933	12 days
1934	16 days
1935	12 days
1936	21 days
1937	15 days
1939	10 days
1940	19 days
1941	20 days
1942	22 days
1943	13 days
1944	17 days
1945	11 days
1946	10 days
1947	10 days
1948	8 days
1949	19 days
1950	8 days
1951	17 days
1952	14 days
1953	18 days
1954	11 days
1955	16 days
1956	12 days
1957	21 days
1958	19 days
1959	13 days
1960	14 days
1961	18 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.

Download the Data

Data for Rio Piedras standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Rio Piedras 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).