Chatham Muni AP Weather Records (USW00094624)

Record envelope, standing records and threshold days for Chatham Muni AP (USW00094624), Massachusetts, United States, with 31 years of record.

Key Facts for Chatham Muni AP

Chatham Muni AP (USW00094624) is a weather station in Massachusetts, United States at 41.69 latitude and -69.99 longitude, 19 m (61 ft) above sea level.
The station reports from 1996 to 2026, 31 years of record.
1,464 records set at Chatham Muni AP still stand.
Records are tracked for no element yet: an element needs 30 years of data to be eligible.

About the Station

Location: Massachusetts, United States, 41.69 latitude, -69.99 longitude.
Elevation: 19 m (61 ft).
Period of record: 1996 to 2026, 31 years.
Eligible elements: none yet.

Daily Record Envelope and 2026

29 days at or beyond a record

The band shows the record high and record low for each calendar day at Chatham Muni AP. The lines show the 2026 daily maximum and minimum. 29 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.

Daily record high and record low at Chatham Muni AP, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	15.0 C (59.0 F)	-20.6 C (-5.1 F)	10.6 C (51.1 F)	-9.3 C (15.3 F)
Feb	17.2 C (63.0 F)	-19.9 C (-3.8 F)	12.8 C (55.0 F)	-8.8 C (16.2 F)
Mar	18.9 C (66.0 F)	-13.2 C (8.2 F)	15.6 C (60.1 F)	-7.1 C (19.2 F)
Apr	29.4 C (84.9 F)	-4.9 C (23.2 F)	22.2 C (72.0 F)	-1.0 C (30.2 F)
May	32.2 C (90.0 F)	-0.6 C (30.9 F)	21.7 C (71.1 F)	3.9 C (39.0 F)
Jun	33.9 C (93.0 F)	5.6 C (42.1 F)	32.2 C (90.0 F)	10.6 C (51.1 F)
Jul	37.2 C (99.0 F)	10.0 C (50.0 F)	31.1 C (88.0 F)	12.8 C (55.0 F)
Aug	36.7 C (98.1 F)	9.4 C (48.9 F)	30.0 C (86.0 F)	10.6 C (51.1 F)
Sep	32.2 C (90.0 F)	2.8 C (37.0 F)	26.1 C (79.0 F)	7.8 C (46.0 F)
Oct	28.3 C (82.9 F)	-2.2 C (28.0 F)	25.6 C (78.1 F)	3.3 C (37.9 F)
Nov	22.8 C (73.0 F)	-8.9 C (16.0 F)	15.6 C (60.1 F)	-3.3 C (26.1 F)
Dec	18.3 C (64.9 F)	-13.8 C (7.2 F)	12.2 C (54.0 F)	-8.3 C (17.1 F)

Which Years Hold Standing Records

1,464 standing records

1,464 records at Chatham Muni AP still stand. 2000 holds the most, with 80.

Standing records at Chatham Muni AP by the year they were set
Year set	Standing records
1996	23
1997	45
1998	35
1999	56
2000	80
2001	59
2002	60
2003	49
2004	51
2005	50
2006	38
2007	46
2008	41
2009	49
2010	57
2011	50
2012	49
2013	32
2014	46
2015	63
2016	63
2017	55
2018	50
2019	35
2020	36
2021	40
2022	62
2023	68
2024	44
2025	32

Wettest Day of Each Month

Sep: 134.6 mm (5.3 in)

The wettest day on record for each calendar month at Chatham Muni AP. The most was 134.6 mm (5.3 in) on 9 September 2021.

Record daily precipitation for each month at Chatham Muni AP
Month	Record daily precipitation (mm)	Date
Jan	56.9 mm (2.2 in)	20 January 2019
Feb	67.3 mm (2.6 in)	5 February 2016
Mar	78.0 mm (3.1 in)	30 March 2003
Apr	67.3 mm (2.6 in)	1 April 2017
May	50.3 mm (2.0 in)	24 May 1999
Jun	87.1 mm (3.4 in)	7 June 2006
Jul	59.2 mm (2.3 in)	4 July 2014
Aug	109.2 mm (4.3 in)	19 August 2017
Sep	134.6 mm (5.3 in)	9 September 2021
Oct	85.1 mm (3.4 in)	26 October 2022
Nov	79.8 mm (3.1 in)	3 November 2007
Dec	70.1 mm (2.8 in)	5 December 2020

Period of Record Coverage

1996 to 2025

30 years of record at Chatham Muni AP, 1996 to 2025. 1 years have data for under 90 percent of days and are left out of rankings: 1996.

Days with data per year at Chatham Muni AP
Year	Days with data	Share of year	Complete
1996	172	47%	No
1997	350	96%	Yes
1998	364	100%	Yes
1999	347	95%	Yes
2000	365	100%	Yes
2001	363	99%	Yes
2002	365	100%	Yes
2003	361	99%	Yes
2004	365	100%	Yes
2005	359	98%	Yes
2006	363	99%	Yes
2007	360	99%	Yes
2008	366	100%	Yes
2009	365	100%	Yes
2010	365	100%	Yes
2011	362	99%	Yes
2012	365	100%	Yes
2013	364	100%	Yes
2014	365	100%	Yes
2015	365	100%	Yes
2016	360	98%	Yes
2017	365	100%	Yes
2018	365	100%	Yes
2019	361	99%	Yes
2020	366	100%	Yes
2021	365	100%	Yes
2022	363	99%	Yes
2023	362	99%	Yes
2024	354	97%	Yes
2025	360	99%	Yes

Latest Records

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

Climate Trend

29 complete years, 1997 to 2025

One stripe for each of 29 complete years at Chatham Muni AP, 1997 to 2025. Blue stripes are years cooler than the station's own mean of 10.9 C (51.5 F); red stripes are warmer. The coolest year was 2003, at 9.5 C (49.0 F), and the warmest was 2023, at 12.9 C (55.3 F). The strongest colour marks a difference of 2.1 C (3.8 F).

Annual mean temperature at Chatham Muni AP as warming stripes, 1997 to 2025
Year	Annual mean temperature	Difference from the station mean
1997	10.3 C	-0.61 C
1998	11.0 C	+0.11 C
1999	10.9 C	+0.02 C
2000	9.7 C	-1.20 C
2001	10.6 C	-0.24 C
2002	10.6 C	-0.28 C
2003	9.5 C	-1.40 C
2004	9.5 C	-1.40 C
2005	10.0 C	-0.89 C
2006	11.5 C	+0.66 C
2007	10.7 C	-0.15 C
2008	10.8 C	-0.10 C
2009	9.9 C	-1.01 C
2010	11.3 C	+0.46 C
2011	11.4 C	+0.58 C
2012	11.7 C	+0.87 C
2013	10.7 C	-0.18 C
2014	10.2 C	-0.67 C
2015	10.3 C	-0.61 C
2016	11.2 C	+0.35 C
2017	11.2 C	+0.30 C
2018	11.0 C	+0.15 C
2019	10.5 C	-0.40 C
2020	11.7 C	+0.83 C
2021	11.6 C	+0.78 C
2022	12.1 C	+1.24 C
2023	12.9 C	+2.08 C
2024	11.8 C	+0.90 C
2025	10.6 C	-0.24 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

1996 to 2026

Yearly extremes at Chatham Muni AP: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	37.2 C (99.0 F)	1999	32.2 C (90.0 F)	31
Coldest night (TNn)	-20.6 C (-5.1 F)	2004	-13.8 C (7.2 F)	31
Wettest day (Rx1day)	134.6 mm (5.3 in)	2021	66.0 mm (2.6 in)	29
Wettest five days (Rx5day)	194.1 mm (7.6 in)	2024	92.2 mm (3.6 in)	29
Longest dry spell (CDD)	37 days	2020	17 days	29

Hottest day (TXx)

The hottest day of the year at Chatham Muni AP, 1996 to 2026. The record is 37.2 C (99.0 F) in 1999, marked on the chart; the median year is 32.2 C (90.0 F).

Hottest day (TXx) at Chatham Muni AP by year
Year	Hottest day (TXx)
1996	28.3 C (82.9 F)
1997	32.8 C (91.0 F)
1998	32.8 C (91.0 F)
1999	37.2 C (99.0 F)
2000	28.9 C (84.0 F)
2001	30.6 C (87.1 F)
2002	32.8 C (91.0 F)
2003	30.6 C (87.1 F)
2004	28.3 C (82.9 F)
2005	31.7 C (89.1 F)
2006	36.7 C (98.1 F)
2007	32.2 C (90.0 F)
2008	32.2 C (90.0 F)
2009	30.0 C (86.0 F)
2010	34.4 C (93.9 F)
2011	32.8 C (91.0 F)
2012	33.9 C (93.0 F)
2013	31.1 C (88.0 F)
2014	29.4 C (84.9 F)
2015	31.7 C (89.1 F)
2016	32.8 C (91.0 F)
2017	31.1 C (88.0 F)
2018	32.8 C (91.0 F)
2019	35.6 C (96.1 F)
2020	33.3 C (91.9 F)
2021	31.7 C (89.1 F)
2022	32.8 C (91.0 F)
2023	32.2 C (90.0 F)
2024	31.1 C (88.0 F)
2025	32.2 C (90.0 F)
2026	33.9 C (93.0 F)

Coldest night (TNn)

The coldest night of the year at Chatham Muni AP, 1996 to 2026. The record is -20.6 C (-5.1 F) in 2004, marked on the chart; the median year is -13.8 C (7.2 F).

Coldest night (TNn) at Chatham Muni AP by year
Year	Coldest night (TNn)
1996	-7.8 C (18.0 F)
1997	-13.3 C (8.1 F)
1998	-11.1 C (12.0 F)
1999	-14.4 C (6.1 F)
2000	-16.7 C (1.9 F)
2001	-8.9 C (16.0 F)
2002	-8.9 C (16.0 F)
2003	-14.4 C (6.1 F)
2004	-20.6 C (-5.1 F)
2005	-13.9 C (7.0 F)
2006	-11.0 C (12.2 F)
2007	-12.7 C (9.1 F)
2008	-11.6 C (11.1 F)
2009	-15.5 C (4.1 F)
2010	-12.1 C (10.2 F)
2011	-13.8 C (7.2 F)
2012	-10.5 C (13.1 F)
2013	-13.8 C (7.2 F)
2014	-15.5 C (4.1 F)
2015	-17.7 C (0.1 F)
2016	-19.9 C (-3.8 F)
2017	-13.8 C (7.2 F)
2018	-14.9 C (5.2 F)
2019	-14.3 C (6.3 F)
2020	-8.8 C (16.2 F)
2021	-10.5 C (13.1 F)
2022	-12.7 C (9.1 F)
2023	-19.3 C (-2.7 F)
2024	-7.7 C (18.1 F)
2025	-9.3 C (15.3 F)
2026	-15.6 C (3.9 F)

Wettest day (Rx1day)

The wettest day of the year at Chatham Muni AP, 1996 to 2026. The record is 134.6 mm (5.3 in) in 2021, marked on the chart; the median year is 66.0 mm (2.6 in).

Wettest day (Rx1day) at Chatham Muni AP by year
Year	Wettest day (Rx1day)
1996	n/a
1997	n/a
1998	41.1 mm (1.6 in)
1999	50.3 mm (2.0 in)
2000	66.0 mm (2.6 in)
2001	67.3 mm (2.6 in)
2002	73.9 mm (2.9 in)
2003	78.0 mm (3.1 in)
2004	93.5 mm (3.7 in)
2005	50.8 mm (2.0 in)
2006	87.1 mm (3.4 in)
2007	79.8 mm (3.1 in)
2008	49.5 mm (1.9 in)
2009	83.8 mm (3.3 in)
2010	56.4 mm (2.2 in)
2011	53.6 mm (2.1 in)
2012	46.5 mm (1.8 in)
2013	46.2 mm (1.8 in)
2014	61.5 mm (2.4 in)
2015	67.3 mm (2.6 in)
2016	67.3 mm (2.6 in)
2017	109.2 mm (4.3 in)
2018	65.3 mm (2.6 in)
2019	56.9 mm (2.2 in)
2020	70.1 mm (2.8 in)
2021	134.6 mm (5.3 in)
2022	85.1 mm (3.4 in)
2023	43.4 mm (1.7 in)
2024	99.6 mm (3.9 in)
2025	34.8 mm (1.4 in)
2026	54.1 mm (2.1 in)

Wettest five days (Rx5day)

The wettest five days of the year at Chatham Muni AP, 1996 to 2026. The record is 194.1 mm (7.6 in) in 2024, marked on the chart; the median year is 92.2 mm (3.6 in).

Wettest five days (Rx5day) at Chatham Muni AP by year
Year	Wettest five days (Rx5day)
1996	n/a
1997	n/a
1998	56.8 mm (2.2 in)
1999	82.3 mm (3.2 in)
2000	78.0 mm (3.1 in)
2001	76.8 mm (3.0 in)
2002	117.6 mm (4.6 in)
2003	95.8 mm (3.8 in)
2004	93.8 mm (3.7 in)
2005	91.8 mm (3.6 in)
2006	144.0 mm (5.7 in)
2007	84.6 mm (3.3 in)
2008	107.9 mm (4.2 in)
2009	92.2 mm (3.6 in)
2010	98.0 mm (3.9 in)
2011	70.4 mm (2.8 in)
2012	73.9 mm (2.9 in)
2013	89.7 mm (3.5 in)
2014	113.9 mm (4.5 in)
2015	114.7 mm (4.5 in)
2016	111.0 mm (4.4 in)
2017	135.8 mm (5.3 in)
2018	85.6 mm (3.4 in)
2019	72.5 mm (2.9 in)
2020	88.4 mm (3.5 in)
2021	145.5 mm (5.7 in)
2022	104.2 mm (4.1 in)
2023	90.2 mm (3.6 in)
2024	194.1 mm (7.6 in)
2025	102.4 mm (4.0 in)
2026	58.5 mm (2.3 in)

Longest dry spell (CDD)

The longest dry spell of the year at Chatham Muni AP, 1996 to 2026. The record is 37 days in 2020, marked on the chart; the median year is 17 days.

Longest dry spell (CDD) at Chatham Muni AP by year
Year	Longest dry spell (CDD)
1996	n/a
1997	n/a
1998	20 days
1999	20 days
2000	10 days
2001	24 days
2002	22 days
2003	10 days
2004	14 days
2005	29 days
2006	20 days
2007	19 days
2008	14 days
2009	20 days
2010	13 days
2011	15 days
2012	19 days
2013	14 days
2014	12 days
2015	24 days
2016	12 days
2017	18 days
2018	18 days
2019	15 days
2020	37 days
2021	16 days
2022	27 days
2023	14 days
2024	17 days
2025	12 days
2026	15 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

29 years with a frost

Across 29 years with a frost, the median last spring frost at Chatham Muni AP falls on 11 April and the median first autumn frost on 6 November, which leaves a median of 211 days between them.

Fitted over all years, the growing season changes by +9.3 days per decade at this station.

Frost dates and growing season at Chatham Muni AP
Measure	Median, all years	Earliest period	Recent period (1997 to 2025)	Recent against earliest	Fitted trend
Last spring frost	11 April	n/a	11 April	n/a	-4.9 days per decade
First autumn frost	6 November	n/a	6 November	n/a	+4.4 days per decade
Growing days	211 days	n/a	211 days	n/a	+9.3 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 Chatham Muni AP standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Chatham Muni AP 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).