Sign In Become a Member
Daily Discussions

Saturday, September 19, 2026

September 19, 2026

BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA SATURDAY, SEPTEMBER 19, 2026 ALL TIMES ARE…

Agreement required — click “Accept & Continue” below to review and accept the Data Use & Privacy Policy

Access to this content requires acceptance of our Data Use & Privacy Policy.

BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

SATURDAY, SEPTEMBER 19, 2026
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0528E
SUNSET:  1747E

A SOLID TASTE OF FALL TODAY WITH MUCH COOLER AND DRIER AIR FOLLOWING
A COLD FRONTAL PASSAGE YESTERDAY….

What a difference today is from yesterday and the day before. In
stead of warm temperatures in the upper 70s to low 80s and high
humidity levels, today is featuring temperatures which are a solid
8-10 degrees below normal, and much drier air. Clear skies this
morning have been overtaken by high clouds by early this afternoon
dimming the sun, however it’s still a spectacular day with
excellent visibility.

As mentioned, temperatures are considerably cooler than yesterday
(around 15F degrees cooler) with readings only reaching the low
to mid 60s by early this afternoon. With dew point values in the
mid 40s today, it definitely has the feel of fall out there. Today
is a perfect day for outdoor activities.

Winds have been fairly light, but steady today, first out the north,
but then veering around to the east-northeast. The average speed
for the day so far is around 8mph. The peak gust for the day so far
is 20mph, which occurred just after midnight.

Visibility has been excellent all day with a view of around 80
miles.

The maximum temperature so far today is 63F, which is 9 degrees
below the normal high of 72F. The minimum temperature since
midnight is 50F, which is 5 degrees below the normal low of 55F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Clear, few stratocumulus distant E-SE, few altocumulus distant
ENE-S-WSW, few cirrus all quadrants
Temperature: 55F; Dew Point: 44F; Relative Humidity: 68%
Wind: NNE @ 5 kts, wind light
Sea-level pressure: 1024.1 mb; 30.24 in. Hg: rising unsteadily
Visibility: 80 miles
6-hr Max temp: 58F
6-hr Min temp: 50F
24-hr Precip: 0.00 inches
BHO SA 1155 CLR 80 241/55/44/0205/024/ FEW SC DSNT E-SE
FEW AC DSNT ENE-S-WSW FEW CI ALQDS WND LGT/ 8/551 52020 10058 20050

10 A.M.
Weather: Scattered altocumulus, broken cirrus, few stratocumulus all
quadrants
Temperature: 61F; Dew Point: 45F; Relative Humidity: 56%
Wind: NE @ 7G14 kts
Sea-level pressure: 1025.0 mb; 30.27 in. Hg: rising, then more slowly
Visibility: 80 miles
3-hr Precip: 0.00 inches
BHO SA 1455 140 SCT 250 BKN 80 250/61/45/0407G14/027/ FEW SC ALQDS/
8/551 51009

1 P.M.
Weather: Broken cirrus, few stratocumulus distant SE-SW, few
altocumulus all quadrants
Temperature: 63F; Dew Point: 47F; Relative Humidity: 56%
Wind: E @ 5 kts, wind light and variable
Sea-level pressure: 1023.7 mb; 30.23 in. Hg: falling, then more slowly
Visibility: 80 miles
6-hr Max temp: 63F
6-hr Min temp: 55F
6-hr Precip: 0.00 inches
BHO SA 1755 E250 BKN 80 237/63/47/0805/023/ FEW SC DSNT SE-SW
FEW AC ALQDS WND L/V/ 8/551 56013 10063 20055

————————————————————–

SUMMARY FOR FRIDAY, SEPTEMBER 18, 2026

TEMPERATURE (DEGREES F)
MAX…….79   NORMAL…..72
MIN…….58   NORMAL…..55
MEAN……69   NORMAL…..63

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+6
TOTAL DEPARTURE FOR THE MONTH (SEP)…………………+10 [+0.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2026 THRU JUN 2027)
TOTAL HEATING UNITS FOR YESTERDAY……………..0  DEPARTURE……..-4
TOTAL HEATING UNITS FOR THE MONTH (SEP)……….16  DEPARTURE…….-19
TOTAL HEATING UNITS FOR THE SEASON……………19  DEPARTURE…….-34
TOTAL HEATING UNITS LAST SEASON TO DATE……….46  DEPARTURE…….-27

COOLING DEGREE DAYS (SEASON: JAN 2026 THRU DEC 2026)
TOTAL COOLING UNITS FOR YESTERDAY……………..4  DEPARTURE……..+2
TOTAL COOLING UNITS FOR THE MONTH (SEP)……….51  DEPARTURE……..-9
TOTAL COOLING UNITS FOR THE SEASON…………..805  DEPARTURE……+150
TOTAL COOLING UNITS LAST SEASON TO DATE………706  DEPARTURE…….+99

PEAK WIND GUST (MPH):
Note: Instruments designated #1 = Main Tower, #2 = South Tower,
F420C, Contacting, Merlin, and Richards are all on Main Tower.
E=Estimated *=Last of multiple occurrences

F420C (Official)………..26 N    @   10:10 P.M.*
VECTOR #1 (1-Sec)……….26 NNW  @   07:35 P.M.
VECTOR #2 (1-Sec)……….27 N    @   07:26 P.M.
DAVIS #1……………….25 NNW  @   07:35 P.M.
DAVIS #2 ………………23 N    @   07:26 P.M.
RMY #1 (Instantaneous)…..27 NNW  @   07:35 P.M.
RMY #2 (Instantaneous)…..29 N    @   07:26 P.M.
MERLIN…………………25 NW
RICHARDS (C5C) (Inst)……26 NNW  @   07:35 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………16 NNW  @   10:34 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..17 NNW  @   07:35 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..17 N    @   07:31 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………16 NW   @   03:03 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………16 N    @   07:32 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..16 N    @   10:51 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..17 N    @   07:31 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………16 NW   @   03:05 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..9.3 NNW [222 total miles] VECTOR #1………………9.8
VECTOR #2……………..10.0
DAVIS #1……………….9.7 NNW
DAVIS #2……………….9.2 NNW
RMY #1…………………9.7 NNW
RMY #2…………………9.8 NW
RICHARDS (C5C)…………10.1

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.14
TOTAL PRECIPITATION FOR THE MONTH (SEP)……..2.04 DEPARTURE…..-0.22
TOTAL PRECIPITATION FOR THE YEAR (2026)…….28.03 DEPARTURE…..-8.84

————————————————————–

PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN)/SUN(%)/PEAK GUST/VEC1/RMY GUST
PEAK GUST: F420C (Official)
VEC1: Vector #1 1-second gust
RMY:  R.M. Young #1 wind gust recording system (Instantaneous)
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

9/1  69/57/63/-6/0.21/008/01             15 SSW VEC1 15 E   RMY 14
9/2  76/58/67/-2/0.00/393/50             21 ESE VEC1 21 ESE RMY 20
9/3  74/60/67/-1/0.45/196/25             24 SSE VEC1 24 SSE RMY 23
9/4  84/63/74/+6/0.00/624/80             24 NNW VEC1 25 NNW RMY 24
9/5  71/60/66/-2/T/412/53                24 ENE VEC1 24 ENE RMY 25
9/6  69/53/61/-7/0.35/364/47             24 NE  VEC1 24 NNE RMY 27
9/7  79/52/66/-1/0.00/732/95             30 NW  VEC1 30 NW  RMY 30
9/8  80/58/69/+2/0.00/546/71             23 WNW VEC1 22 NNW RMY 24
9/9  80/58/69/+2/0.02/130/17             36 SSW VEC1 36 SSW RMY 36
9/10 84/67/76/+10/T/641/84               44 W   VEC1 43 W   RMY 47
9/11 77/59/68/+2/0.00/654/86             23 NW  VEC1 23 NW  RMY 25
9/12 77/55/66/0/0.00/667/88              23 SSW VEC1 23 SSW RMY 22
9/13 67/60/64/-1/0.98/000/00             25 SE  VEC1 26 SE  RMY 24
9/14 72/53/63/-2/T/572/76                32 NNW VEC1 32 NNW RMY 34
9/15 68/48/58/-7/0.00/727/97             18 S   VEC1 18 SE  RMY 18
9/16 78/53/66/+2/0.00/522/70             21 SW  VEC1 21 WSW RMY 21
9/17 82/63/73/+9/0.03/…/..             25 SW  VEC1 25 SW  RMY 27
9/18 79/58/69/+6/T/…/..                26 N   VEC1 26 NNW RMY 27

9/19 The low since midnight is 50F, the daily normal low is 55F.

————————————————————–

SEPTEMBER DAILY RECORDS TO DATE

NONE.

————————————————————–

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)

RECORDS FOR SEPTEMBER 19
HIGH 87F IN 1906,1983
LOW 37F IN 1929
PRECIP 3.69 INCHES IN 1936
PEAK GUST 55 MPH S IN 2012

RECORDS FOR SEPTEMBER 20
HIGH 90 IN 1983
LOW 34 IN 1979
PRECIP 4.57 INS IN 1899
PEAK GUST 44 MPH NE IN 1972

TODAY’S REPORT PREPARED BY: Matt Douglas

Please follow and like us:
Blue Hill Observatory & Science Center · Legal

Data Use & Privacy Policy

Please read the full Policy before accessing Observatory data · Effective January 1, 2025

Notice: By accessing, downloading, or using any Blue Hill Observatory data or services, you unconditionally accept and agree to be bound by this Policy in its entirety. If you do not agree, you may not access or use Observatory data.
Effective January 1, 2025 · Milton, Massachusetts · bluehill.live
Part I — Data Use Policy
§ 01

Ownership and Proprietary Rights

All observational records, compiled datasets, metadata, database structures, and related materials provided by the Blue Hill Observatory & Science Center are the exclusive property of the Blue Hill Observatory & Science Center. The Observatory has maintained continuous weather observations at the summit of Great Blue Hill since 1885, and the entirety of that record — its compilation, structure, curation, and organization — constitutes a proprietary database protected under applicable United States law, including copyright law and common law database protections.

All rights not expressly granted in this Policy are reserved by the Observatory. No access to or use of Observatory data shall be construed as a waiver of any rights or as a license to use data beyond the scope expressly stated herein.

§ 02

Governing Law and Jurisdiction

This Policy shall be governed by and construed in accordance with the laws of the Commonwealth of Massachusetts, without regard to its conflict of law provisions. For interactions with international users, this Policy shall apply to the maximum extent permitted by applicable local law.

Any dispute arising from or related to this Policy shall be subject to the exclusive jurisdiction of the state and federal courts located in Norfolk County, Massachusetts. By accessing Observatory data, all users consent to personal jurisdiction in Massachusetts and waive any objection to the venue or inconvenience of such forum.

§ 03

Permitted Uses

Observatory data are made available for the following limited, non-commercial purposes only:

  • Personal study and analysis
  • Educational classroom use
  • Student projects
  • Non-commercial academic research
  • Publication of analyses, figures, models, or conclusions derived from the data, subject to the attribution requirements of Section 4

All other uses require prior written authorization from the Observatory.

§ 04

Attribution Requirement

Any use of Observatory data in any published, presented, or publicly distributed work must include the following verbatim acknowledgment:

“Data provided by the Blue Hill Observatory & Science Center, Milton, Massachusetts. Continuous weather observations since 1885.”

Failure to include proper attribution is a material violation of this Policy.

§ 05

Prohibited Uses

Unless explicitly authorized in writing, Users may not:

  • Resell, license, sublicense, or commercially exploit Observatory data in any form
  • Redistribute the dataset in whole or in part to any third party
  • Publish the dataset for download by third parties
  • Host, mirror, or archive the dataset on any external website, repository, or storage service
  • Upload the dataset to any public or institutional data repository
  • Provide the data through APIs, automated services, or subscription platforms
  • Incorporate the data into any commercial product, software, application, or service
  • Use the data for AI or machine learning systems intended for commercial use or external distribution
  • Use the data to create derivative datasets that enable reconstruction of the underlying observations
§ 06

Commercial Licensing

Organizations seeking to use Observatory data for commercial purposes must obtain a license prior to any such use. Licensing inquiries: data@bluehill.live.

§ 07

Automated Access

Automated scraping, bulk harvesting, or systematic downloading of Observatory data is strictly prohibited without prior written authorization.

§ 08

Enforcement and Remedies

Violation of this Policy may result in immediate revocation of data access, pursuit of legal remedies available under United States law, and referral to applicable authorities. The Observatory reserves all rights to seek injunctive relief, damages, and attorneys’ fees in connection with any unauthorized use of its data.

Part II — Privacy Policy
§ 09–10

Scope & Information Collected

This section governs the collection, use, storage, and disclosure of personal information from visitors to the Blue Hill Observatory website and users of its data services. The Observatory may collect contact information (name, email, organization) when voluntarily submitted, usage data including IP addresses and pages visited, and data download records.

§ 11–12

How We Use Information & Retention

Information is used solely for: responding to inquiries and licensing requests; monitoring and enforcing compliance with this Policy; improving website performance; and communicating Observatory news to opted-in users. The Observatory does not sell, rent, or share personal information with third parties for marketing purposes. Data access records may be retained indefinitely for compliance and enforcement purposes.

§ 13

International Users and Data Transfers

The Observatory is located in the United States. International users acknowledge their information will be processed in the United States under U.S. law. Users requiring specific data processing agreements under non-US law must contact data@bluehill.live before accessing data.

§ 14–16

Cookies, Security & Children’s Privacy

The Observatory website may use cookies for analytics and functionality. By continuing to use the site, users consent to cookie use. The Observatory implements reasonable measures to protect personal information but cannot guarantee absolute security. Observatory data services are not directed at children under 13.

Part III — General Provisions
§ 17–20

Modifications, Severability, Entire Agreement & Contact

The Observatory reserves the right to modify this Policy at any time. Updated versions will be posted at bluehill.live. Continued use of Observatory data following any modification constitutes acceptance of the revised Policy. This Policy constitutes the entire agreement between the User and the Observatory. Questions and licensing inquiries: Blue Hill Observatory & Science Center, Milton, Massachusetts — data@bluehill.live

By accessing, downloading, or using any Blue Hill Observatory data or services, you acknowledge that you have read, understood, and agree to be bound by this Policy.
Effective January 1, 2025 · Blue Hill Observatory & Science Center · Milton, Massachusetts