Sign In Become a Member
Donate
Daily Discussions

Friday, September 5, 2025

September 5, 2025

BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA FRIDAY, SEPTEMBER 5, 2025 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

FRIDAY, SEPTEMBER 5, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0514E
SUNSET:  1811E

EARLY MORNING RAIN LEAVES BEHIND HUMID CONDITIONS, BREEZY
SOUTHERLY WIND….

We received our first precipitation for the month of September
during the early morning hours today, with a total of 0.12″ of
rain. While not a lot, anything helps, as we are sitting at
around -3.62 inches in deficit for the year.

The skies immediately after the rain had featured some fog and
a mix of altocumulus and cirrus, and by mid morning we had overcast
stratocumulus. By the afternoon we finally had some clearing, with
broken cumulus clouds throughout the sky.

Temperatures overnight only dropped to 62F, with a low of 64F as
of midnight. After the passing early morning rain and the added
sunshine, we were experiencing quite a different feel, as dew
points also have increased unto the upper 60s. Temperatures
themselves have also increased only a few degrees higher than
yesterday, however, the dew point increase is what has made it
feel so much warmer today. The southerly wind bringing warmer and
more moist air has also added to the ‘stickiness factor’.

The wind picked up yesterday late afternoon and has continued
to be a steady southerly to south-southwesterly flow for much of
the day. The average speed has been around 12mph for the day
so far. The peak gust for the day so far is around 28mph, which
occurred during the overnight hours, at 12:22am.

Visibility has improved as the lingering clouds moved out of
the region. We fluctuated from about 12 miles of visibility in
the early morning to about 30 miles by the early afternoon.

The maximum temperature so far today is 81F degrees, which is
4 degrees above the normal high of 77F. The minimum temperature
since midnight is 62 degrees, which is 3 degrees above the normal
low of 59F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Broken stratus, broken altocumulus, broken cirrus,
sun dimly visible
Temperature: 65F; Dew Point: 65F; Relative Humidity: 100%
Wind: S @ 8 kts
Sea-level pressure: 1014.4 mb; 29.96 in. Hg: rising unsteadily
Visibility: 12 miles, fog all quadrants
6-hr Max temp: 65F
6-hr Min temp: 62F
24-hr Precip: 0.12 inches
BHO SA 1155 E6 BKN 180 BKN 250 BKN 12 144/65/65/1808/996/
THN F ALQDS SUN DMLY VSBL/ 8/651 52005 6012/ 70012 10065 20062

10 A.M.
Weather: Overcast stratocumulus
Temperature: 70F; Dew Point: 68F; Relative Humidity: 100%
Wind: SSW @ 10 kts
Sea-level pressure: 1014.9 mb; 29.97 in. Hg: falling, then
steady
Visibility: 30 miles
3-hr Precip: 0.00 inches
BHO SA 1455 E30 OVC 30 150/70/68/1910/997/ 8/5// 51006

1 P.M.
Weather: Broken cumulus
Temperature: 80F Dew Point: 65F; Relative Humidity: 60%
Wind: SSW @ 12 kts
Sea-level pressure: 1013.7 mb; 29.93 in. Hg: steady, then
falling
Visibility: 30 miles
6-hr Max temp: 81F
6-hr Min temp: 65F
6-hr Precip: 0.00 inches
BHO SA 1755 E35 BKN 30 137/80/65/2012/993/ 8/200 58013
10081 20065

————————————————————–

SUMMARY FOR THURSDAY, SEPTEMBER 4, 2025

TEMPERATURE (DEGREES F)
MAX…….81   NORMAL…..77
MIN…….56   NORMAL…..59
MEAN……69   NORMAL…..68

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….+1
TOTAL DEPARTURE FOR THE MONTH……………………….-5 [-1.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2025 THRU JUN 2026)
TOTAL HEATING UNITS FOR YESTERDAY……………..0  DEPARTURE……..-1
TOTAL HEATING UNITS FOR THE MONTH……………..1  DEPARTURE……..-3
TOTAL HEATING UNITS FOR THE SEASON……………21  DEPARTURE……..-1
TOTAL HEATING UNITS LAST SEASON TO DATE……….14  DEPARTURE……..+7

COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..4  DEPARTURE………0
TOTAL COOLING UNITS FOR THE MONTH…………….10  DEPARTURE……..-8
TOTAL COOLING UNITS FOR THE SEASON…………..682  DEPARTURE…….+68
TOTAL COOLING UNITS LAST SEASON TO DATE………710  DEPARTURE…….-28

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

F420C (Official)………..26 SSW  @   04:43 P.M.
VECTOR #1 (1-Sec)……….27 SSW  @   04:43 P.M.
VECTOR #2 (1-Sec)……….29 SSW  @   04:48 P.M.
DAVIS #1……………….27 S    @   03:34 P.M.
DAVIS #2 ………………37 S    @   04:48 P.M.
RMY #1 (Instantaneous)…..28 SSW  @   07:19 P.M.
RMY #2 (Instantaneous)…..30 SSW  @   04:48 P.M.
MERLIN…………………25 SSW
RICHARDS (C5C) (Inst)……26 SSW  @   07:19 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………20 S    @   04:38 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..19 SSW  @   03:10 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..20 S    @   04:38 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………19 S    @   04:38 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………23 S    @   04:56 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..19 SSW  @   03:10 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..20 S    @   04:38 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………18 SSW  @   03:10 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..10.2 S [245 total miles] VECTOR #1………………10.5
VECTOR #2………………11.1
DAVIS #1……………….10.0 SSW
DAVIS #2……………….11.4 SSW
RMY #1…………………10.1 SSW
RMY #2…………………11.1 SSW
RICHARDS (C5C)………….10.1

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.12 DEPARTURE……0.00
TOTAL PRECIPITATION FOR THE MONTH…………..0.12 DEPARTURE…..-0.34
TOTAL PRECIPITATION FOR THE YEAR (2025)…….31.45 DEPARTURE…..-3.62

————————————————————–

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   73/55/64/-5/0.00/221/28            23 NE  VEC1 23 ENE RMY 23
9/2   77/58/68/-1/0.00/714/91            18 ESE VEC1 19 ESE RMY 18
9/3   78/57/68/0/0.00/719/92             21 SSW VEC1 21 SSW RMY 21
9/4   81/56/69/+1/0.00/…/..            26 SSW VEC1 27 SSW RMY 28

9/5 The low since midnight is 62F, the daily normal low is 59F.

————————————————————–

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 5
HIGH 90F IN 1971
LOW 45F IN 1906
PRECIP 1.37 INCHES IN 1907
PEAK GUST 46 MPH NW IN 1994

RECORDS FOR SEPTEMBER 6
HIGH 92F IN 1900, 2018
LOW 39F IN 1888
PRECIP 3.19 INCHES IN 1890
PEAK GUST 78e MPH SE IN 1979 (TROPICAL STORM DAVID)

TODAY’S REPORT PREPARED BY: Amanda Joly

facebookShare on Facebook
TwitterPost on X
FollowFollow us
PinterestSave
←
→
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.org
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.org.

§ 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.org 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.org. 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.org

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
↓ Scroll to read the full Policy — the agreement checkbox will unlock at the bottom
Main Menu