What Winter Does to Capital Region Masonry: Freeze-Thaw by the Numbers
Last reviewed 2026-07-25. Journalists, researchers, and community groups are welcome to cite any figure on this page with attribution and a link.
The Capital Region combines one of the oldest housing stocks in America with a climate that crosses freezing about 95 times a year. That combination — water in old masonry, freezing and thawing over and over — is the quiet engine behind most chimney and brick repair in Albany, Troy, and the surrounding towns. This page collects the verified numbers. Every figure links to its source at the bottom.
It pairs with our practical companion, The Capital Region Chimney Field Guide.
~95
Days a year Albany crosses back and forth over 32°F (derived from NWS climate normals)
NWS Albany, 1991–2020 normals
53.5%
Of Troy's housing was built before 1940
U.S. Census ACS 2019–2023
59.2 in
Albany's normal annual snowfall
NWS Albany
~50%
Of U.S. residential heating fires are confined chimney/flue fires (national figure)
U.S. Fire Administration, 2017–2019
The freeze-thaw climate
NWS climate normals for Albany (1991–2020) show 135.7 days a year with a low at or below freezing — but only 41.1 days that stay below freezing all day. The difference, roughly 95 days a year, is the freeze-thaw zone: days the temperature crosses 32°F, letting water in masonry freeze, expand, thaw, and refreeze. (That ~95 figure is our arithmetic on the two published normals; no agency publishes an official 'cycle count.')
The rest of the winter ledger: 59.2 inches of normal annual snowfall, 6,357 normal heating degree days, a record low of −28°F (January 19, 1971), a record 46.7-inch storm in March 1888, and a 15-day stretch that never rose above 0°F in 1961. Albany's weather record runs back to 1874, and it is a masonry stress test.
The oldest housing stock upstate
Concentrated history raises the stakes: the Central Troy Historic District alone holds 659 contributing buildings across roughly 96 acres, with building stock spanning 1787 to about 1940 (1986 National Register nomination). Historic Albany Foundation — founded in 1974 after more than 1,500 buildings were demolished for the Empire State Plaza and I-787 — still shepherds the region's masonry, including the $1.7 million restoration of the ca.-1728 Van Ostrande-Radliff House, upstate New York's oldest urban building.
| Place | Housing built before 1940 | Share | Median year built |
|---|---|---|---|
| Troy | 13,408 of 25,066 units | 53.5% | 1939 or earlier |
| Albany (city) | 21,766 of 50,709 units | 42.9% | 1949 |
| Albany County | 39,633 of 146,959 units | 27.0% | — |
U.S. Census ACS 2019–2023 5-year tables B25034/B25035; percentages computed from the published counts.
What freeze-thaw does to brick (per the National Park Service)
The NPS Preservation Briefs — the federal standards for historic masonry — are unambiguous. Brief 39: 'Uncontrolled moisture is the most prevalent cause of deterioration in older and historic buildings,' explicitly including 'spalled masonry from freeze-thaw action.' It also warns against chloride de-icers, which 'can increase freeze/thaw spalling of masonry' — worth remembering before salting a stoop or chimney base.
Brief 2, on repointing: 'A good repointing job is meant to last, at least 30 years, and preferably 50–100 years' — while the wrong mortar traps moisture in the wall and damages the brick itself. That's the difference between a repoint and a patch, and why cheap patch jobs on 100-year-old Capital Region brick fail in a few winters.
The chimney-fire connection
National fire data puts numbers to the risk (these are U.S. figures, not local): the U.S. Fire Administration counted 34,200 residential heating fires a year in 2017–2019, and about half were 'chimney or flue fire, confined to chimney or flue.' NFPA's analysis adds that failure to clean — principally creosote in chimneys — was a factor in 27% of home heating fires, fireplaces or chimneys were involved in 32%, and nearly half of all heating fires occur December through February.
Locally, the flues are busy: Census data counts 1,339 Albany County homes heating primarily with wood and 9,086 with fuel oil — over 10,000 households whose heat exhausts through a chimney every winter day. Add the ~95 annual freeze-thaw crossings working on the masonry around those flues, and late summer — before masons book out — is the right time for the ground-level check our field guide walks through.
Sources & Methodology
Every figure above was taken from the primary sources below (accessed 2026-07-25). Where a number is derived (arithmetic on published figures) or covers a broader period or area, the text says so.
- NWS Albany — 2025 Annual Climate Report (1991–2020 normals) — freezing days, snowfall, heating degree days
- NWS Albany — station climate extremes (1874–present)
- U.S. Census Bureau ACS 2019–2023 — year structure built, Albany city (B25034)
- U.S. Census Bureau ACS 2019–2023 — year structure built, Troy (B25034)
- U.S. Census Bureau ACS 2019–2023 — year structure built, Albany County (B25034)
- U.S. Census Bureau ACS 2019–2023 — house heating fuel, Albany County (B25040)
- NPS Preservation Brief 39 — controlling unwanted moisture
- NPS Preservation Brief 2 — repointing mortar joints
- U.S. Fire Administration — heating fires in residential buildings, 2017–2019 — national figures
- NFPA — home fires involving heating equipment (2012–2016; .gov-hosted copy) — national figures
- Central Troy Historic District — 1986 National Register nomination (as reproduced)
- Historic Albany Foundation — history and 48 Hudson restoration
Quick Answers
How many freeze-thaw cycles does Albany get a year?
No agency publishes an official cycle count, but the NWS normals let you derive it: Albany averages 135.7 days with a freezing low but only 41.1 days that stay frozen all day — so on roughly 95 days a year the temperature crosses 32°F. Each crossing lets water in masonry freeze, expand about 9%, and thaw again.
How old are Capital Region homes really?
Older than almost anywhere upstate: 53.5% of Troy's housing and 42.9% of Albany's was built before 1940 (Census ACS 2019–2023), with Troy's median home dating to 1939 or earlier. The Central Troy Historic District alone contains 659 contributing buildings, some dating to 1787.
How long should repointing actually last?
Per the National Park Service's Preservation Brief 2: 'A good repointing job is meant to last, at least 30 years, and preferably 50–100 years.' The catch is mortar match — modern portland-heavy mortar on old soft brick traps moisture and accelerates the very freeze-thaw damage it's meant to stop.
Are chimney fires actually common?
Nationally, yes — about half of the 34,200 annual U.S. residential heating fires in 2017–2019 were confined chimney or flue fires (USFA), and NFPA found failure to clean (mostly creosote) was a factor in 27% of home heating fires. Locally, more than 10,000 Albany County households heat primarily with wood or fuel oil — all of it venting through chimneys.