Heat Pumps & Mini Splits by State

Maine has the highest per-capita heat pump adoption rate in the US — not by accident. Heating oil is dominant (60%+ of homes) and expensive, making heat pump payback among the best in the country. Winters are long and cold (coastal lows near 0°F, Aroostook County below -20°F), summers mild. Efficiency Maine's rebate program is aggressive and well-funded.

New Hampshire is cold and heating-dominant — Manchester winters see sustained stretches in the teens, northern NH (Berlin, Colebrook) can drop to -20°F. Summers are mild. Oil and propane heat are still common and make heat pump retrofits highly cost-effective.

Vermont is cold and rural — Burlington winters see sustained stretches in the teens and Northeast Kingdom drops below -20°F. Summers are mild. Heating oil, propane, and wood are dominant, making heat pump retrofits highly cost-effective.

Massachusetts has one of the most aggressive state-level electrification pushes in the US — MassSave incentives can exceed $10,000 for a qualifying whole-home heat pump install. Winters in Boston see sustained stretches in the teens with occasional dips to near zero; summers are hot and humid in July-August.

Rhode Island is a coastal New England climate — cold winters (teens at coldest), humid summers in the mid-80s. Salt air along Narragansett Bay is a factor for outdoor units. Oil heat is still common, making heat pump retrofits cost-effective.

Connecticut combines cold winters (teens to single digits on coldest nights) with humid summers in the mid-80s. Coastal CT (Fairfield, New Haven) is a touch milder than northern CT (Litchfield, Windham). Home heating is dominated by oil and propane, which makes heat pump retrofits especially cost-effective — oil at $4/gal runs 3x the operating cost of a properly sized heat pump.

New York's climate ranges from mild NYC/Long Island through cold upstate (Syracuse, Buffalo see lake-effect winters) to the genuinely arctic Adirondacks. NYSERDA runs one of the country's most aggressive electrification programs, and the state's Climate Leadership and Community Protection Act mandates heat pump adoption.

New Jersey splits between the cooler north (Newark, Paterson) and warmer south (Cherry Hill, Atlantic City). Winters see lows in the teens statewide with periodic polar intrusions; summers are humid mid-80s. Coastal areas need salt-resistant outdoor units.

Pennsylvania spans cool Philadelphia/Pittsburgh through cold Erie (lake-effect snow) to frigid mountain towns (State College, Scranton). Natural gas heating is dominant statewide; electric heat pumps are increasingly cost-competitive as gas prices normalize.

Delaware sits in the transition between the cold Northeast and the humid mid-Atlantic. Winters see overnight lows around 20°F, summers mid-80s and muggy. Coastal areas (Rehoboth, Lewes) are milder. The state is small enough that there is essentially one climate to design for.

Maryland spans the Appalachian west (Deep Creek, Cumberland) which is colder and mountainous, and the Chesapeake east which is mild and humid. Baltimore and DC suburbs see summers in the 90s and winters into the teens. Salt air affects the Eastern Shore.

Virginia climate spans mountains (Appalachian southwest, cold winters) through Piedmont (Richmond, Charlottesville — mild) to Tidewater (Norfolk, Virginia Beach — humid and mild). Summer humidity is the common challenge statewide.

West Virginia is Appalachian — hilly, humid in summer, cold in winter. Charleston and Huntington see moderate winters with lows in the 20s; Snowshoe and higher elevations see genuine winter. Coal-fired electricity means heat pump economics are slightly less favorable than in hydro-heavy states.

North Carolina spans hot humid coast (Wilmington, Outer Banks) through Piedmont (Charlotte, Raleigh) with mild winters and hot summers, to cool mountains (Asheville, Boone) with real winter. Ice storms are the Piedmont's biggest HVAC reliability issue.

South Carolina summers are long, hot, and humid — especially along the coast (Charleston, Myrtle Beach). Winters are mild except for the Upstate (Greenville, Spartanburg) which sees the occasional teens. Saltwater corrosion is a serious coastal concern.

Georgia summers run long and humid — Atlanta hits 90°F from June through September with 60–70°F dew points. Winters are mild but not trivial; north Georgia (Blue Ridge) sees lows in the teens. Coastal Georgia (Savannah, Brunswick) behaves more like Florida. Gas heat is common statewide but the operating-cost gap vs heat pump has closed.

Florida is the most cooling-dominant state in the continental US. Summer dew points exceed 75°F for four months, hurricane-season humidity lingers from June through October, and even winter afternoons routinely hit 75°F in the southern half of the state. Heating is almost an afterthought except for a handful of nights per year in the panhandle. Saltwater corrosion on coastal condensers is a design-level concern — spec'd outdoor units need coastal/marine-rated coils.

Kentucky winters drop to the teens overnight on coldest days, summers hit 90°F with Ohio Valley humidity. Eastern Kentucky coalfield towns run slightly colder; far-western Kentucky (Paducah) is warmer and more humid. Coal-heat legacy is strong but heat pumps now dominate new installs.

Tennessee has mild-to-moderate winters and humid summers — Nashville and Memphis see 90°F+ July with high dew points, and lows in the 20s on coldest winter nights. East Tennessee mountains (Gatlinburg, Knoxville) are slightly colder and wetter.

Alabama summers run long and muggy, with Gulf-influenced dew points above 70°F from June through September and peak highs in the mid-90s. Winters are short and mild, rarely dropping below 20°F except in northern counties. Humidity is the real HVAC challenge here — more so than raw cooling load — which favors variable-capacity heat pumps that can dehumidify at part load rather than fixed-speed systems that short-cycle.

Mississippi summers are as humid as anywhere in the US — Jackson and Hattiesburg both see sustained 75°F+ dew points. Winters are mild; coldest nights hit the low 20s in northern counties, rarely below 30°F on the coast.

Ohio sees cold lake-effect winters in the north (Cleveland, Toledo) and milder Ohio Valley winters in the south (Cincinnati). Summers are mid-80s and humid. Heating dominates the annual load in the north; more balanced in the south.

Michigan's Lower Peninsula sees cold winters with lake-effect snow, summers with Great Lakes humidity. The Upper Peninsula is genuinely cold — Houghton and Marquette winters can see -20°F lows. Heating dominates the annual load statewide.

Indiana is a mixed-humid state — Indianapolis winters see lows in the 10s, summers mid-80s with Midwest humidity. Northern Indiana (Fort Wayne, South Bend) is colder with lake-effect snow. Southern Indiana (Evansville) sits on the Ohio River and runs warmer year-round.

Illinois spans the climate line between the cold upper Midwest (Chicago, Rockford) and the temperate Ohio River valley (Carbondale, Metropolis). Chicago winters regularly dip to -10°F with wind chill, summers to the low 90s with Great Lakes humidity. Southern Illinois sees milder winters and hotter, more humid summers.

Wisconsin winters are genuinely cold — Milwaukee and Madison see sustained stretches in the teens, northern Wisconsin (Superior, Rhinelander) drops well below zero. Summers are warm and humid with Great Lakes moisture. Focus on Energy runs one of the more generous state heat pump programs.

Minnesota is one of the coldest populous states — Minneapolis sees multiple weeks per winter below 0°F, International Falls routinely hits -40°F. Summers are warm and humid. Heat pumps have traditionally been viewed skeptically here, but modern hyper-heat units are changing that.

Iowa is solid cold-winter territory — Des Moines overnight lows regularly hit 0°F, with weeks of sub-zero highs during polar vortex events. Summers are hot and humid with corn-country dew points exceeding 75°F. Wind is significant year-round and affects real-world heat pump performance at low ambient.

Missouri sits at a climate crossroads — Kansas City and St. Louis see summers in the 90s with Midwest humidity and winters in the teens. The Ozarks (Springfield, Branson) are slightly milder. Ice storms are the real reliability concern.

North Dakota is among the coldest US states — Fargo winters routinely dip below -20°F with wind-chills below -40°F. Summers are warm and short. Propane heat is dominant in rural areas; heat pumps make economic sense when replacing propane but require hyper-heat class equipment.

South Dakota summers are hot and windy with 90°F+ stretches; winters are cold and dry with Sioux Falls lows in the single digits and polar-vortex excursions to -15°F. Black Hills (Rapid City) is slightly milder due to elevation effects.

Nebraska is plains country — cold windy winters, hot humid summers in the east, hot dry summers in the west. Omaha and Lincoln see winters in the teens with polar vortex excursions to -10°F. Western Nebraska (Scottsbluff, North Platte) is drier but equally cold.

Kansas winters are cold and windy — Wichita lows in the 20s routinely, western Kansas drops below zero. Summers push 100°F in the southwest with low humidity, mid-90s and more humid in the east. Wind from the plains is a design factor for outdoor unit placement.

Texas summers are the defining HVAC challenge — Houston, San Antonio, and Austin see 3,000+ cooling degree days annually with long stretches above 100°F. The 2021 winter storm revealed that heat pumps need to handle sub-20°F events too. Panhandle (Amarillo, Lubbock) is genuinely cold in winter.

Oklahoma sees hot humid summers (100°F+ a few weeks per year), mild winters with occasional ice storms, and significant wind year-round. OKC and Tulsa handle 15–25 sub-freezing nights per winter. Panhandle is drier and colder.

Arkansas is firmly in the humid subtropical belt — summers in the 90s with high dew points, winters mild with brief Arctic intrusions down to 10°F a few nights a year. The Ozark region (Fayetteville, Bentonville) sees slightly colder and drier winters than the Delta or south. Ice storms are the real reliability concern more than absolute cold.

Louisiana summers are among the most humid in America — New Orleans dew points sit in the mid-70s for four months, with hurricane-season rain adding indoor humidity challenges. Winters are mild (30s at coldest), so heating is secondary. Saltwater corrosion along the coast and in the Mississippi Delta is a serious condenser concern.

New Mexico is high-elevation dry — Albuquerque sits at 5,300 ft and sees cold winter nights (low 20s) but mild days. Santa Fe and Taos are colder and snowier. Southern NM (Las Cruces) is warmer. Low humidity makes evaporative cooling a viable supplement.

Arizona's HVAC picture splits in two: the desert south (Phoenix, Tucson, Yuma) where summer highs routinely exceed 110°F and cooling is the entire game, and the northern high country (Flagstaff, Prescott, the rim) where winters drop below 10°F and heating matters. In the desert zone, cooling runs 8 months a year — SEER2 efficiency has a huge lifetime payback. In the north, a cold-climate heat pump replaces propane heat at roughly 60% the operating cost.

Montana is cold, dry, and windy. Billings and Bozeman winters see sustained sub-zero stretches; mountain valleys are colder still. Summers are warm but short with low humidity. Heating dominates the annual load, but summer cooling is becoming more common with warmer trends.

Idaho stretches from the high desert (Boise, Twin Falls) through mountain country into the wet panhandle (Coeur d'Alene). Winters in Boise see overnight lows in the teens; Sandpoint and the mountain valleys drop below zero for sustained stretches. Summers are dry — low humidity means evaporative cooling supplements can lower cooling loads on heat pumps.

Wyoming is high-elevation cold — Cheyenne at 6,000 ft sees winter lows below 0°F, Jackson and Yellowstone are colder still. Summers are warm and dry with cool nights. Low humidity statewide.

Colorado's Front Range (Denver, Colorado Springs, Boulder) sees dry cold winters with overnight lows around 10°F and summer highs in the low 90s. The Western Slope (Grand Junction) is milder. Mountain towns (Breckenridge, Aspen, Steamboat) are Zone 6-7 with sustained sub-zero stretches. Low humidity statewide makes evaporative cooling viable as a supplement, but electric heat pumps still win on total annual operating cost versus gas.

Utah is high-desert dry. Salt Lake City winters drop into the teens, summers hit the mid-90s with low humidity. Mountain towns (Park City, Vernal) are Zone 6. St. George in the southwest is hot like Las Vegas. Dry air favors evaporative supplements but heat pumps still dominate total cost.

Nevada splits into desert south (Las Vegas, Henderson) where cooling dominates and 115°F summer days are routine, and Reno/Carson City where winters see snow and lows in the 20s. Humidity is uniformly low, which favors inverter heat pumps but also allows evaporative cooling supplements.

Washington is bimodal — maritime Pacific (Seattle, Tacoma) rarely drops below freezing, summers are mild; eastern Washington (Spokane, Tri-Cities) is high desert with real winters and hot dry summers. Statewide, Washington requires heat pumps in most new construction per state energy code.

Oregon divides sharply at the Cascades. Western Oregon (Portland, Eugene) is maritime — mild wet winters rarely below 30°F, cool dry summers with occasional 100°F heat waves. Eastern Oregon (Bend, Pendleton) is high desert with cold winters and hot dry summers.

California spans more IECC climate zones than any other state. Coastal cities (SF, LA beachside) rarely need cooling or heating. Inland valleys (Sacramento, Fresno, Bakersfield) see 100°F+ summers and mild winters. The Sierras and far-north coast see real cold with snow. The desert (Palm Springs, Indio) mirrors southern Arizona. State law is aggressively pushing electrification — Title 24 effectively requires heat pumps in new construction.

Alaska's HVAC reality is unique in the US — Fairbanks sees ambient temps below -40°F several weeks per year, and even Anchorage logs 100+ days a year below 32°F. Summer cooling is largely a non-issue outside the southeast panhandle. The question for every Alaska buyer is which heat pump still produces rated capacity at -13°F or colder, and whether it pairs with a backup heat source (typically oil or wood).

Hawaii has the most expensive residential electricity in the US (30–40¢/kWh) and the mildest year-round climate, which combines to make high-efficiency inverter heat pumps or mini splits the single highest-return HVAC upgrade anywhere in America. Trade winds mean many Hawaii homes have no heating or cooling at all — but Kona-side and interior Oahu rooms can benefit from cooling on humid days.