Rend Lake Dam Weather Records (USC00117187)

Record envelope, standing records and threshold days for Rend Lake Dam (USC00117187), Illinois, United States, with 53 years of record.

Key Facts for Rend Lake Dam

Rend Lake Dam (USC00117187) is a weather station in Illinois, United States at 38.04 latitude and -88.99 longitude, 139 m (455 ft) above sea level.
The station reports from 1974 to 2026, 53 years of record.
1,464 records set at Rend Lake Dam still stand.
Records are tracked for prcp, snow, snwd: an element needs 30 years of data to be eligible.
Rend Lake Dam set a daily record precipitation of 35.4 mm (1.4 in) on 11 July 2026.

About the Station

Location: Illinois, United States, 38.04 latitude, -88.99 longitude.
Elevation: 139 m (455 ft).
Period of record: 1974 to 2026, 53 years.
Eligible elements: prcp, snow, snwd.

Daily Record Envelope and 2026

20 days at or beyond a record

The band shows the record high and record low for each calendar day at Rend Lake Dam. The lines show the 2026 daily maximum and minimum. 20 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.

Daily record high and record low at Rend Lake Dam, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	21.1 C (70.0 F)	-28.3 C (-18.9 F)	20.0 C (68.0 F)	-19.4 C (-2.9 F)
Feb	26.1 C (79.0 F)	-23.3 C (-9.9 F)	23.3 C (73.9 F)	-12.2 C (10.0 F)
Mar	31.7 C (89.1 F)	-20.0 C (-4.0 F)	31.7 C (89.1 F)	-7.8 C (18.0 F)
Apr	33.9 C (93.0 F)	-4.4 C (24.1 F)	30.6 C (87.1 F)	1.7 C (35.1 F)
May	34.4 C (93.9 F)	0.0 C (32.0 F)	31.1 C (88.0 F)	3.3 C (37.9 F)
Jun	37.2 C (99.0 F)	7.2 C (45.0 F)	n/a	n/a
Jul	38.9 C (102.0 F)	10.0 C (50.0 F)	n/a	n/a
Aug	40.0 C (104.0 F)	8.9 C (48.0 F)	n/a	n/a
Sep	36.7 C (98.1 F)	2.2 C (36.0 F)	n/a	n/a
Oct	34.4 C (93.9 F)	-5.0 C (23.0 F)	n/a	n/a
Nov	28.3 C (82.9 F)	-13.3 C (8.1 F)	n/a	n/a
Dec	24.4 C (75.9 F)	-23.3 C (-9.9 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Rend Lake Dam still stand. 1976 holds the most, with 74.

Standing records at Rend Lake Dam by the year they were set
Year set	Standing records
1974	41
1975	49
1976	74
1977	72
1978	60
1979	67
1980	53
1981	51
1982	41
1983	69
1984	60
1985	50
1986	54
1987	34
1988	1
2009	7
2010	37
2013	39
2014	53
2015	70
2016	44
2017	54
2018	63
2019	42
2020	49
2021	47
2022	33
2023	23
2024	43
2025	55
2026	29

All-Time Record Progression

1 new records

1 all-time records were set at Rend Lake Dam between 23 December 2004 and 23 December 2004. Each dot is a new record.

Wettest Day of Each Month

Nov: 231.1 mm (9.1 in)

The wettest day on record for each calendar month at Rend Lake Dam. The most was 231.1 mm (9.1 in) on 14 November 1993.

Record daily precipitation for each month at Rend Lake Dam
Month	Record daily precipitation (mm)	Date
Jan	83.8 mm (3.3 in)	20 January 1990
Feb	106.9 mm (4.2 in)	1 February 1982
Mar	101.1 mm (4.0 in)	28 March 1977
Apr	199.6 mm (7.9 in)	29 April 1996
May	82.3 mm (3.2 in)	1 May 2017
Jun	110.5 mm (4.4 in)	17 June 2000
Jul	89.4 mm (3.5 in)	4 July 1981
Aug	107.7 mm (4.2 in)	29 August 1974
Sep	88.9 mm (3.5 in)	8 September 2018
Oct	88.9 mm (3.5 in)	9 October 2009
Nov	231.1 mm (9.1 in)	14 November 1993
Dec	101.3 mm (4.0 in)	3 December 1982

Period of Record Coverage

1974 to 2026

31 years of record at Rend Lake Dam, 1974 to 2026. 17 years have data for under 90 percent of days and are left out of rankings: 1974, 1980, 1987, 1988, 2009, 2010, 2013, 2014 and others.

Days with data per year at Rend Lake Dam
Year	Days with data	Share of year	Complete
1974	264	72%	No
1975	334	92%	Yes
1976	366	100%	Yes
1977	365	100%	Yes
1978	364	100%	Yes
1979	362	99%	Yes
1980	295	81%	No
1981	362	99%	Yes
1982	333	91%	Yes
1983	335	92%	Yes
1984	335	92%	Yes
1985	329	90%	Yes
1986	336	92%	Yes
1987	228	62%	No
1988	16	4%	No
2009	118	32%	No
2010	323	88%	No
2013	212	58%	No
2014	305	84%	No
2015	316	87%	No
2016	306	84%	No
2017	302	83%	No
2018	343	94%	Yes
2019	291	80%	No
2020	366	100%	Yes
2021	365	100%	Yes
2022	159	44%	No
2023	228	62%	No
2024	293	80%	No
2025	317	87%	No
2026	123	34%	No

Latest Records

Latest records at Rend Lake Dam
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
11 July 2026	Rend Lake Dam, US	daily rain	35.4 mm (1.4 in)	11.3 mm (0.4 in)	4 years	13 of 100 (Routine)
8 July 2026	Rend Lake Dam, US	daily rain	71.7 mm (2.8 in)	43.8 mm (1.7 in)	15 years	38 of 100 (Notable)
26 January 2026	Rend Lake Dam, US	monthly snow depth	30.5 cm (12.0 in)	15.3 cm (6.0 in)	32 years	39 of 100 (Notable)
1 December 2025	Rend Lake Dam, US	daily snowfall	0.3 cm (0.1 in)	0.3 cm (0.1 in)	51 years	20 of 100 (Routine)
19 February 2025	Rend Lake Dam, US	daily snowfall	7.6 cm (3.0 in)	7.6 cm (3.0 in)	43 years	32 of 100 (Routine)
19 February 2025	Rend Lake Dam, US	daily snow depth	7.6 cm (3.0 in)	7.6 cm (3.0 in)	42 years	20 of 100 (Routine)
11 January 2025	Rend Lake Dam, US	monthly snowfall	12.7 cm (5.0 in)	0.5 cm (0.2 in)	28 years	24 of 100 (Routine)
29 December 2024	Rend Lake Dam, US	daily rain	34.5 mm (1.4 in)	7.6 mm (0.30 in)	9 years	13 of 100 (Routine)
29 July 2024	Rend Lake Dam, US	daily rain	40.6 mm (1.6 in)	19.8 mm (0.8 in)	48 years	32 of 100 (Routine)
17 July 2024	Rend Lake Dam, US	daily rain	51.1 mm (2.0 in)	14.3 mm (0.6 in)	3 years	14 of 100 (Routine)
6 May 2024	Rend Lake Dam, US	daily rain	24.6 mm (1.0 in)	8.9 mm (0.35 in)	21 years	17 of 100 (Routine)
26 March 2024	Rend Lake Dam, US	daily rain	35.6 mm (1.4 in)	3.3 mm (0.13 in)	9 years	9 of 100 (Routine)
28 January 2024	Rend Lake Dam, US	daily rain	31.8 mm (1.3 in)	13.5 mm (0.5 in)	29 years	25 of 100 (Routine)
24 January 2024	Rend Lake Dam, US	daily rain	19.1 mm (0.8 in)	2.1 mm (0.08 in)	2 years	6 of 100 (Routine)
2 July 2023	Rend Lake Dam, US	daily rain	38.6 mm (1.5 in)	1.0 mm (0.04 in)	9 years	7 of 100 (Routine)
24 March 2023	Rend Lake Dam, US	daily rain	55.4 mm (2.2 in)	23.4 mm (0.9 in)	4 years	23 of 100 (Routine)
26 July 2022	Rend Lake Dam, US	daily rain	25.4 mm (1.0 in)	5.3 mm (0.21 in)	43 years	19 of 100 (Routine)
17 February 2022	Rend Lake Dam, US	daily rain	33.5 mm (1.3 in)	12.2 mm (0.5 in)	24 years	20 of 100 (Routine)
16 February 2022	Rend Lake Dam, US	daily rain	32.5 mm (1.3 in)	11.7 mm (0.5 in)	4 years	14 of 100 (Routine)
18 December 2021	Rend Lake Dam, US	daily rain	40.6 mm (1.6 in)	16.5 mm (0.6 in)	31 years	26 of 100 (Routine)

Extremes by Year

1974 to 2026

Yearly extremes at Rend Lake Dam: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	40.0 C (104.0 F)	1980	36.7 C (98.1 F)	31
Coldest night (TNn)	-28.3 C (-18.9 F)	1977	-18.9 C (-2.0 F)	31
Wettest day (Rx1day)	231.1 mm (9.1 in)	1993	67.3 mm (2.6 in)	53
Wettest five days (Rx5day)	290.9 mm (11.5 in)	1993	101.6 mm (4.0 in)	53
Longest dry spell (CDD)	37 days	1999	20 days	53

Hottest day (TXx)

The hottest day of the year at Rend Lake Dam, 1974 to 2026. The record is 40.0 C (104.0 F) in 1980, marked on the chart; the median year is 36.7 C (98.1 F).

Hottest day (TXx) at Rend Lake Dam by year
Year	Hottest day (TXx)
1974	36.7 C (98.1 F)
1975	36.1 C (97.0 F)
1976	37.8 C (100.0 F)
1977	37.8 C (100.0 F)
1978	38.9 C (102.0 F)
1979	35.0 C (95.0 F)
1980	40.0 C (104.0 F)
1981	36.7 C (98.1 F)
1982	35.6 C (96.1 F)
1983	39.4 C (102.9 F)
1984	36.7 C (98.1 F)
1985	36.7 C (98.1 F)
1986	37.8 C (100.0 F)
1987	38.3 C (100.9 F)
1988	19.4 C (66.9 F)
1989	n/a
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	28.3 C (82.9 F)
2010	38.9 C (102.0 F)
2011	n/a
2012	n/a
2013	36.7 C (98.1 F)
2014	35.6 C (96.1 F)
2015	36.7 C (98.1 F)
2016	36.7 C (98.1 F)
2017	36.1 C (97.0 F)
2018	35.6 C (96.1 F)
2019	36.1 C (97.0 F)
2020	34.4 C (93.9 F)
2021	35.0 C (95.0 F)
2022	37.2 C (99.0 F)
2023	37.8 C (100.0 F)
2024	38.3 C (100.9 F)
2025	37.2 C (99.0 F)
2026	31.7 C (89.1 F)

Coldest night (TNn)

The coldest night of the year at Rend Lake Dam, 1974 to 2026. The record is -28.3 C (-18.9 F) in 1977, marked on the chart; the median year is -18.9 C (-2.0 F).

Coldest night (TNn) at Rend Lake Dam by year
Year	Coldest night (TNn)
1974	-15.0 C (5.0 F)
1975	-15.0 C (5.0 F)
1976	-21.7 C (-7.1 F)
1977	-28.3 C (-18.9 F)
1978	-20.0 C (-4.0 F)
1979	-22.2 C (-8.0 F)
1980	-18.9 C (-2.0 F)
1981	-19.4 C (-2.9 F)
1982	-25.0 C (-13.0 F)
1983	-23.3 C (-9.9 F)
1984	-23.3 C (-9.9 F)
1985	-20.0 C (-4.0 F)
1986	-15.0 C (5.0 F)
1987	-7.2 C (19.0 F)
1988	-16.7 C (1.9 F)
1989	n/a
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	-11.7 C (10.9 F)
2010	-18.9 C (-2.0 F)
2011	n/a
2012	n/a
2013	-16.7 C (1.9 F)
2014	-18.9 C (-2.0 F)
2015	-20.0 C (-4.0 F)
2016	-15.0 C (5.0 F)
2017	-17.2 C (1.0 F)
2018	-20.0 C (-4.0 F)
2019	-17.8 C (0.0 F)
2020	-18.3 C (-0.9 F)
2021	-19.4 C (-2.9 F)
2022	-15.0 C (5.0 F)
2023	-8.9 C (16.0 F)
2024	-17.8 C (0.0 F)
2025	-17.8 C (0.0 F)
2026	-19.4 C (-2.9 F)

Wettest day (Rx1day)

The wettest day of the year at Rend Lake Dam, 1974 to 2026. The record is 231.1 mm (9.1 in) in 1993, marked on the chart; the median year is 67.3 mm (2.6 in).

Wettest day (Rx1day) at Rend Lake Dam by year
Year	Wettest day (Rx1day)
1974	107.7 mm (4.2 in)
1975	66.3 mm (2.6 in)
1976	45.7 mm (1.8 in)
1977	101.1 mm (4.0 in)
1978	62.2 mm (2.4 in)
1979	43.9 mm (1.7 in)
1980	45.0 mm (1.8 in)
1981	96.5 mm (3.8 in)
1982	106.9 mm (4.2 in)
1983	82.6 mm (3.3 in)
1984	67.6 mm (2.7 in)
1985	79.2 mm (3.1 in)
1986	71.9 mm (2.8 in)
1987	63.2 mm (2.5 in)
1988	85.3 mm (3.4 in)
1989	68.3 mm (2.7 in)
1990	83.8 mm (3.3 in)
1991	78.7 mm (3.1 in)
1992	38.1 mm (1.5 in)
1993	231.1 mm (9.1 in)
1994	50.8 mm (2.0 in)
1995	46.7 mm (1.8 in)
1996	199.6 mm (7.9 in)
1997	63.5 mm (2.5 in)
1998	103.1 mm (4.1 in)
1999	66.8 mm (2.6 in)
2000	110.5 mm (4.4 in)
2001	25.4 mm (1.0 in)
2002	50.8 mm (2.0 in)
2003	56.4 mm (2.2 in)
2004	57.4 mm (2.3 in)
2005	71.1 mm (2.8 in)
2006	71.6 mm (2.8 in)
2007	83.8 mm (3.3 in)
2008	54.4 mm (2.1 in)
2009	88.9 mm (3.5 in)
2010	55.9 mm (2.2 in)
2011	78.2 mm (3.1 in)
2012	67.3 mm (2.6 in)
2013	66.8 mm (2.6 in)
2014	83.8 mm (3.3 in)
2015	62.2 mm (2.4 in)
2016	67.3 mm (2.6 in)
2017	82.3 mm (3.2 in)
2018	88.9 mm (3.5 in)
2019	63.2 mm (2.5 in)
2020	53.3 mm (2.1 in)
2021	52.8 mm (2.1 in)
2022	47.0 mm (1.9 in)
2023	55.4 mm (2.2 in)
2024	51.1 mm (2.0 in)
2025	32.5 mm (1.3 in)
2026	71.7 mm (2.8 in)

Wettest five days (Rx5day)

The wettest five days of the year at Rend Lake Dam, 1974 to 2026. The record is 290.9 mm (11.5 in) in 1993, marked on the chart; the median year is 101.6 mm (4.0 in).

Wettest five days (Rx5day) at Rend Lake Dam by year
Year	Wettest five days (Rx5day)
1974	160.1 mm (6.3 in)
1975	101.6 mm (4.0 in)
1976	82.7 mm (3.3 in)
1977	111.5 mm (4.4 in)
1978	79.2 mm (3.1 in)
1979	99.1 mm (3.9 in)
1980	86.1 mm (3.4 in)
1981	130.0 mm (5.1 in)
1982	178.2 mm (7.0 in)
1983	201.5 mm (7.9 in)
1984	86.4 mm (3.4 in)
1985	133.3 mm (5.2 in)
1986	117.4 mm (4.6 in)
1987	99.9 mm (3.9 in)
1988	90.9 mm (3.6 in)
1989	114.3 mm (4.5 in)
1990	105.6 mm (4.2 in)
1991	114.5 mm (4.5 in)
1992	58.7 mm (2.3 in)
1993	290.9 mm (11.5 in)
1994	97.1 mm (3.8 in)
1995	72.2 mm (2.8 in)
1996	214.6 mm (8.4 in)
1997	123.2 mm (4.9 in)
1998	142.7 mm (5.6 in)
1999	94.3 mm (3.7 in)
2000	158.3 mm (6.2 in)
2001	59.7 mm (2.4 in)
2002	76.8 mm (3.0 in)
2003	91.4 mm (3.6 in)
2004	97.9 mm (3.9 in)
2005	82.5 mm (3.2 in)
2006	133.6 mm (5.3 in)
2007	84.6 mm (3.3 in)
2008	99.5 mm (3.9 in)
2009	109.0 mm (4.3 in)
2010	112.0 mm (4.4 in)
2011	233.3 mm (9.2 in)
2012	111.5 mm (4.4 in)
2013	83.9 mm (3.3 in)
2014	113.3 mm (4.5 in)
2015	88.4 mm (3.5 in)
2016	153.4 mm (6.0 in)
2017	258.6 mm (10.2 in)
2018	136.3 mm (5.4 in)
2019	120.9 mm (4.8 in)
2020	95.0 mm (3.7 in)
2021	95.9 mm (3.8 in)
2022	66.0 mm (2.6 in)
2023	56.1 mm (2.2 in)
2024	89.2 mm (3.5 in)
2025	57.5 mm (2.3 in)
2026	113.7 mm (4.5 in)

Longest dry spell (CDD)

The longest dry spell of the year at Rend Lake Dam, 1974 to 2026. The record is 37 days in 1999, marked on the chart; the median year is 20 days.

Longest dry spell (CDD) at Rend Lake Dam by year
Year	Longest dry spell (CDD)
1974	13 days
1975	15 days
1976	25 days
1977	19 days
1978	17 days
1979	24 days
1980	15 days
1981	20 days
1982	12 days
1983	27 days
1984	15 days
1985	19 days
1986	21 days
1987	19 days
1988	21 days
1989	22 days
1990	25 days
1991	24 days
1992	28 days
1993	17 days
1994	17 days
1995	25 days
1996	19 days
1997	17 days
1998	22 days
1999	37 days
2000	19 days
2001	28 days
2002	25 days
2003	25 days
2004	31 days
2005	32 days
2006	18 days
2007	28 days
2008	18 days
2009	17 days
2010	20 days
2011	16 days
2012	13 days
2013	23 days
2014	25 days
2015	24 days
2016	20 days
2017	29 days
2018	18 days
2019	26 days
2020	16 days
2021	22 days
2022	15 days
2023	17 days
2024	13 days
2025	17 days
2026	14 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.

Rainfall Return Levels

30 years, 1975 to 2021

A day with at least 67.0 mm (2.6 in) of rain is expected about once in 2 years. A day with at least 250.9 mm (9.9 in) of rain is expected about once in 100 years.

Rainfall return levels at Rend Lake Dam: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	67.0 mm (2.6 in)
5 years	94.5 mm (3.7 in)
10 years	119.2 mm (4.7 in)
25 years	160.6 mm (6.3 in)
50 years	200.7 mm (7.9 in)	Longer than the 30 years of record
100 years	250.9 mm (9.9 in)	Longer than the 30 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, 30 years of values from 1975 to 2021.

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: 231.1 mm (9.1 in) in 1993; 199.6 mm (7.9 in) in 1996; 103.1 mm (4.1 in) in 1998.

Download the Data

Data for Rend Lake Dam standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Rend Lake Dam 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 2026-10-14 (14 October 2026). Records are computed by this site and are not official.

Data as of 2026-10-12. Last revised 12 October 2026 (2026-10-12).