State guides · Climate · Freeze-thaw
Freeze-thaw cycles by state and ZIP code
How many days a year the air drops to freezing and climbs back above it where you live, from NOAA’s 1991–2020 climate normals for 7,246 weather stations in all 50 states. Those swings are what concrete, pavers and wall block have to stand up to.
A freeze-thaw day has a low at or below 32°F and a high above 32°F. NOAA’s big-city stations average anywhere from none a year (Los Angeles, Honolulu) to about 138 (Cheyenne). Central Pennsylvania gets about 87 to 110: State College 87, Williamsport 95, Lock Haven 109, Renovo 110.
The quick lookup uses the nearest of 1,369 stations built into this page: NOAA’s 1,160 weather-service (USW) stations, which include the first-order and most airport stations, plus every Pennsylvania station and the stations with the most and fewest freeze-thaw days in each state. The live button asks NOAA’s data service for all stations near you. Your ZIP goes to the U.S. Census Bureau to find its center; nothing is stored.
Among Pennsylvania’s 160 NOAA stations, freeze-thaw days run from 50 at Philadelphia’s Franklin Institute to 131 at Clarence. Our area sits in the middle of that range: Renovo (110) and Lock Haven (109) are in the state’s top third, Lewisburg (106) is above the state median (about 102), and Williamsport (95) is just below it. State College has fewer (87) because more of its days stay below freezing all day: about 35 ice days, against 29 at Lock Haven and 27 at Williamsport.
What the columns mean: freezing nights have a low at or below 32°F, ice days have a high at or below 32°F (it stays frozen all day), and freeze-thaw days are freezing nights that thaw by afternoon.
Pennsylvania stations
Big cities: most and fewest
Each state’s big-city station from NOAA’s normals, ranked by average freeze-thaw days a year.
| Station | Freeze-thaw days |
|---|---|
| Cheyenne, WY | 138 |
| Denver Intl AP, CO | 134 |
| Concord Muni AP, NH | 121 |
| Portland Intl Jetport, ME | 103 |
| Billings Logan Intl AP, MT | 102 |
| Hartford Bradley Intl AP, CT | 97 |
| Sioux Falls, SD | 96 |
| Omaha Eppley Airfield, NE | 94 |
| Boise Air Terminal, ID | 92 |
| Salt Lake City Intl AP, UT | 91 |
| Station | Freeze-thaw days |
|---|---|
| Honolulu Intl AP, HI | 0 |
| Los Angeles Intl AP, CA | 0 |
| Phoenix Sky Harbor Intl AP, AZ | 1 |
| New Orleans Intl AP, LA | 5 |
| Charleston City, SC | 6 |
| Las Vegas McCarran AP, NV | 10 |
| Houston Intercont AP, TX | 10 |
| Jacksonville, FL | 14 |
| Seattle Tacoma Intl AP, WA | 24 |
| Portland Intl AP, OR | 30 |
The 10 NOAA stations with the most
All ten are high western sites. At the other end, 89 of NOAA’s 7,246 stations average zero freeze-thaw days.
| NOAA station | Freeze-thaw days | Elevation (ft) |
|---|---|---|
| Bodie California St Historic P, CA | 280 | 8,370 |
| Warren, ID | 258 | 5,910 |
| Boca, CA | 258 | 5,580 |
| Sargents, CO | 256 | 8,460 |
| Sagehen Creek, CA | 254 | 6,340 |
| Spring Valley SP, NV | 247 | 5,950 |
| Truckee-Tahoe AP, CA | 241 | 5,900 |
| Chemult, OR | 240 | 4,760 |
| Tuolumne Meadows RS, CA | 239 | 8,690 |
| Ft Valley, AZ | 234 | 7,350 |
Freeze-thaw days by state
The big-city station is the state’s main city airport or city station. Most and fewest are among all of NOAA’s stations in that state, so mountain, valley and shoreline sites often set them. D.C. uses Washington Reagan National, which NOAA lists under Virginia. Where stations tie, the table names one: California, Florida and Hawaii have 16, 28 and 45 stations at zero, and Iowa, Texas and Wyoming each have a two-way tie.
| State | NOAA stations | Big-city station | Freeze-thaw days | Most in state | Fewest in state |
|---|---|---|---|---|---|
| Alabama | 118 | Birmingham AP, AL | 46 | Hamilton 3 S, AL (94) | Dauphin Is #2, AL (4) |
| Alaska | 192 | Anchorage Intl AP, AK | 82 | Seward 8 NW, AK (164) | Kotzebue Ralph Wein AP, AK (45) |
| Arizona | 175 | Phoenix Sky Harbor Intl AP, AZ | 1 | Ft Valley, AZ (234) | Yuma MCAS, AZ (0) |
| Arkansas | 112 | Little Rock, AR | 36 | Lead Hill, AR (97) | Texarkana Webb Fld, AR (35) |
| California | 374 | Los Angeles Intl AP, CA | 0 | Bodie California St Historic P, CA (280) | San Francisco Dwtn, CA (0) |
| Colorado | 234 | Denver Intl AP, CO | 134 | Sargents, CO (256) | Cortez 8 SE, CO (101) |
| Connecticut | 23 | Hartford Bradley Intl AP, CT | 97 | W Thompson Lake, CT (127) | Bridgeport Sikorsky Mem AP, CT (73) |
| Delaware | 7 | Wilmington New Castle Co AP, DE | 78 | Newark Ag Farm, DE (87) | Lewes, DE (54) |
| District of Columbia | n/a | Washington Reagan AP, VA | 53 | n/a | n/a |
| Florida | 176 | Jacksonville, FL | 14 | Crestview Bob Sikes AP, FL (39) | Bahia Honda SP, FL (0) |
| Georgia | 126 | Atlanta Hartsfield Intl AP, GA | 35 | Blairsville Exp Stn, GA (100) | Brunswick Malcolm McKinnon AP, GA (8) |
| Hawaii | 48 | Honolulu Intl AP, HI | 0 | Mauna Loa 5 NNE, HI (34) | Glenwood #2 55.4, HI (0) |
| Idaho | 144 | Boise Air Terminal, ID | 92 | Warren, ID (258) | Lewiston Nez Perce Co AP, ID (68) |
| Illinois | 170 | Chicago Ohare Intl AP, IL | 78 | Mt Carroll, IL (111) | Chicago Northerly Is, IL (58) |
| Indiana | 117 | Indianapolis, IN | 76 | Wanatah 2 WNW, IN (106) | Evansville Museum, IN (59) |
| Iowa | 150 | Des Moines Intl AP, IA | 82 | Battle Creek 3NE, IA (112) | Ft Madison, IA (75) |
| Kansas | 176 | Wichita, KS | 87 | Brewster 4W, KS (148) | Pittsburg, KS (74) |
| Kentucky | 97 | Louisville Intl AP, KY | 61 | W Liberty 3NW, KY (127) | Eddyville 5S, KY (51) |
| Louisiana | 98 | New Orleans Intl AP, LA | 5 | Monroe 26 N, LA (58) | Boothville ASOS, LA (2) |
| Maine | 82 | Portland Intl Jetport, ME | 103 | Hollis, ME (134) | Frenchville Aroostook AP, ME (79) |
| Maryland | 43 | Baltimore Wash Intl AP, MD | 83 | Sines Deep Creek, MD (125) | Md Sci Ctr Baltimore, MD (43) |
| Massachusetts | 69 | Boston Logan Intl AP, MA | 69 | Birch Hill Dam, MA (138) | Chatham, MA (66) |
| Michigan | 213 | Detroit Metro AP, MI | 78 | Champion Van Riper Pk, MI (132) | NW Michigan Rsch Farm, MI (66) |
| Minnesota | 182 | Minneapolis/St Paul AP, MN | 75 | Tower 2S, MN (118) | La Crescent Dam 7, MN (62) |
| Mississippi | 94 | Jackson Intl AP, MS | 39 | Iuka, MS (91) | Biloxi, MS (11) |
| Missouri | 171 | Kansas City Intl AP, MO | 81 | Steelville 2 N, MO (122) | Portageville, MO (59) |
| Montana | 245 | Billings Logan Intl AP, MT | 102 | Wise Rvr 3 WNW, MT (220) | Wolf Point 34 NE, MT (91) |
| Nebraska | 184 | Omaha Eppley Airfield, NE | 94 | Agate 3 E, NE (174) | Omaha #1, NE (87) |
| Nevada | 119 | Las Vegas McCarran AP, NV | 10 | Spring Valley SP, NV (247) | Laughlin, NV (3) |
| New Hampshire | 55 | Concord Muni AP, NH | 121 | Plymouth, NH (143) | Mt Washington, NH (75) |
| New Jersey | 48 | Newark Intl AP, NJ | 65 | Lambertville, NJ (125) | Margate, NJ (39) |
| New Mexico | 175 | Albuquerque Intl AP, NM | 91 | Luna RS, NM (231) | Carlsbad Caverns, NM (40) |
| New York | 176 | New York Cntrl Pk Twr, NY | 51 | Rhinebeck 4SE, NY (158) | New York Laguardia AP, NY (48) |
| North Carolina | 187 | Charlotte Douglas AP, NC | 57 | Cataloochee, NC (124) | Frisco 2NNE, NC (15) |
| North Dakota | 125 | Fargo Hector Intl AP, ND | 80 | Hettinger Exp Stn, ND (141) | Grafton, ND (68) |
| Ohio | 130 | Columbus Port Columbus Intl AP, OH | 76 | Waterloo, OH (113) | Cleveland Burke AP, OH (57) |
| Oklahoma | 193 | Oklahoma City Will Rogers AP, OK | 65 | Kenton, OK (132) | Ardmore, OK (43) |
| Oregon | 190 | Portland Intl AP, OR | 30 | Chemult, OR (240) | Brookings 2 SE, OR (2) |
| Pennsylvania | 160 | Philadelphia Intl AP, PA | 64 | Clarence, PA (131) | Phila Franklin Inst, PA (50) |
| Rhode Island | 11 | Providence T F Green AP, RI | 89 | Kingston, RI (115) | Newport Rose, RI (73) |
| South Carolina | 103 | Charleston City, SC | 6 | Jocassee 8 WNW, SC (111) | Charleston City, SC (6) |
| South Dakota | 167 | Sioux Falls, SD | 96 | Rochford 2 WNW, SD (208) | Webster, SD (78) |
| Tennessee | 148 | Nashville Intl AP, TN | 60 | Mt Leconte, TN (115) | Memphis Intl AP, TN (41) |
| Texas | 477 | Houston Intercont AP, TX | 10 | Dalhart 6 SW, TX (143) | S Padre Is, TX (0) |
| Utah | 174 | Salt Lake City Intl AP, UT | 91 | Hatch, UT (219) | St George, UT (63) |
| Vermont | 45 | Burlington Intl AP, VT | 88 | Cavendish, VT (135) | Mt Mansfield, VT (69) |
| Virginia | 125 | Norfolk Intl AP, VA | 38 | Mill Gap, VA (134) | Norfolk NAS, VA (30) |
| Washington | 156 | Seattle Tacoma Intl AP, WA | 24 | Glenwood #2, WA (179) | Port Townsend, WA (13) |
| West Virginia | 99 | Charleston Yeager AP, WV | 79 | Marlinton, WV (133) | Bluefield Mercer Co AP, WV (71) |
| Wisconsin | 205 | Milwaukee Mitchell AP, WI | 73 | North Pelican, WI (127) | Racine, WI (68) |
| Wyoming | 158 | Cheyenne, WY | 138 | Darwin Rch, WY (209) | Sundance 8 NNW, WY (105) |
What it means for pavers, walls and concrete
Concrete pavers made to ASTM C936 have to meet freeze-thaw durability criteria, including resistance to deicing salts, tested under ASTM C1645. The standard also has an optional colder test for regions with severe freezing (CMHA). In a high-count area, ask which test your paver line passed (our advice). Deicer rules by brand: ice melt for pavers.
Dry-cast segmental retaining wall block is tested for freeze-thaw resistance under ASTM C1262, in plain water or a 3% salt solution depending on how the block will be used. Its scope points to ASTM C1372, the specification for the block itself. A wall beside a salted driveway is the salt case (our read). Sizes and specs by brand: retaining wall block chart.
NRMCA’s CIP 2 says concrete exposed to freezing should be air-entrained, with about 6% total air for ¾- or 1-inch stone, that deicers should stay off it the first winter and be used in moderation after, and that a breathable silane or siloxane sealer is worth considering once the surface is reasonably dry. Plan the pour with our concrete cure calculator and concrete guide.
Freeze-thaw days count air-temperature swings at the surface. How deep frost goes into the ground is a different number, and it’s what footing depth is based on: frost line depth by state and ZIP code. For planting and seasonal timing: frost dates by state.
How we counted
NOAA’s 1991–2020 normals give each station’s average number of days a year with a low at or below 32°F and with a high at or below 32°F. A day whose high stays at or below 32°F also has a low at or below 32°F, so the first count minus the second is the average number of days with a low at or below freezing and a high above it. GLISA lists a high above 32°F with a low below 32°F as one of the commonly used definitions of a freeze-thaw cycle. NOAA’s counts use “at or below,” so a day that bottoms out at exactly 32°F counts here; GLISA’s own count tallies each crossing of 32°F instead. NOAA doesn’t publish a freeze-thaw count, so the subtraction is ours.
What it misses: days that cross 32°F more than once, the difference between air at the weather station and the surface of your pavement, and whether anything was wet when it froze. These are 30-year averages, so any one winter can differ. NOAA’s normals include both day counts for 7,246 stations in the 50 states; we left out Puerto Rico and the other territories.
Questions
What is a freeze-thaw cycle?
A day when the temperature drops to freezing or below and climbs back above it. On this page a freeze-thaw day is any day with a low at or below 32°F and a high above 32°F, counted from NOAA’s 1991–2020 climate normals. GLISA, a Great Lakes climate program, notes that these swings can damage roads and cause potholes.
How many freeze-thaw days does central Pennsylvania get?
About 87 to 110 a year at the NOAA stations around us: State College 87, Williamsport 95, Lewisburg 106, Lock Haven 109 and Renovo 110. State College has fewer because more of its winter days stay below freezing all day (about 35, against 29 at Lock Haven). Across Pennsylvania’s 160 stations the range is 50 (Philadelphia’s Franklin Institute) to 131 (Clarence).
Where in the U.S. are freeze-thaw cycles worst?
High western valleys and mountains. Bodie, California, at about 8,370 feet, leads NOAA’s stations with about 280 a year. Among big-city stations, Cheyenne (138) and Denver (134) lead, while Los Angeles and Honolulu average none. 89 NOAA stations average zero.
Are freeze-thaw days the same as frost depth?
No. Freeze-thaw days count how often the air crosses 32°F. Frost depth is how far freezing reaches into the ground, and it is what local codes use to set footing depth. See our frost line depth by state and ZIP code guide.
What should I build differently where freeze-thaw days are high?
Use materials tested for it. Concrete pavers made to ASTM C936 have to meet freeze-thaw and deicing-salt durability criteria (CMHA), and segmental retaining wall block is tested for freeze-thaw resistance under ASTM C1262. For poured concrete, NRMCA’s CIP 2 calls for air-entrained concrete and no deicers the first winter.
Why does my ZIP show a station miles away?
The quick lookup uses the nearest of the 1,369 stations built into this page: NOAA’s 1,160 weather-service (USW) stations, which include the first-order and most airport stations, plus every Pennsylvania station and the stations with the most and fewest freeze-thaw days in each state. Tap the live button to check every NOAA station within about 25 miles. A station at a different elevation can differ a lot, as the mountain stations at the top of the national list show.
Building in central Pennsylvania?
We build paver patios, retaining walls and concrete in Lock Haven, Williamsport, State College and the towns around them, where NOAA’s stations average about 87 to 110 freeze-thaw days a year.
Contact us or call (570) 397-9800
Sources: NOAA NCEI U.S. Climate Normals 1991–2020 (annual/seasonal normals, dataset normals-annualseasonal-1991-2020, pulled through NCEI’s Access Data Service); NCEI annual/seasonal normals documentation (day-count definitions, ≤ 32°F); GLISA, Freeze-Thaw Cycles; CMHA PAV-FAQ-001-18; ASTM C1262; NRMCA CIP 2, Scaling Concrete Surfaces (copy hosted by the Tennessee Concrete Association); U.S. Census Bureau TIGERweb (ZIP centers).
Planning information, not a survey or engineering. NOAA’s numbers are averages for weather stations, not your yard. Call 811 and check with your local office before you dig. Last checked November 13, 2026.
Using this guide? Link to it or cite it. It’s free to use with a link back, and we keep it updated against official sources.
Cite as: Muthler Landscaping & Construction, “Freeze-Thaw Cycles by State and ZIP Code: Where Concrete and Pavers Have the Hardest Life,” https://muthlerlandscaping.com/state-guides/freeze-thaw-cycles/ (last checked November 13, 2026).
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