Photo: Ammodramus · Public domainPrecipitation in Hyannis trails that of 89% of U.S. towns: 21 inches a year
The depth of winter brings overnight lows near 13°. In January, nights here are colder than in 89% of U.S. towns. Compared with 1901–2000, the average now sits 1.3° higher. Radiators earn their keep from October to April, the months that average under 50°.
A year in Hyannis at a glance
Each month’s typical high and low, and what it brings.
What stands out about Hyannis’ climate
Compared with towns across the U.S., with Hyannis’ place in Nebraska beside it.
What a year in Hyannis feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 155 frost-free days a year
In half of years the last 32° night comes by May 4 and the first by October 8. Frost and day counts come from NOAA’s station at Whitman 5 Ene, NE, 17 miles from the town’s center, at about the same height.
The 2023 USDA map puts Hyannis’ center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −16°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 21 inches of rain a year
June is the wettest month and January the driest.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Hyannis
91% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Whitman 5 Ene, NE.
Living with Hyannis’ climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
155 frost-free days in zone 5a. The last frost comes by May 4 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 8.
Months with highs of 62–84° and lows of 40° or more: May, June and September.
Parks & trails →Of the yearly building losses FEMA expects in Hyannis from natural hazards, river flooding is the largest share (39%); heat waves, cold waves, winter storms and ice storms together are 13%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Hyannis and similar climates
TownRatings has no climate map of the towns around Hyannis yet.
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Hyannis averaged 1.3° warmer than the 1900s. The biggest change is in January (+3.5°).
A smaller shift than in 55% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Hyannis compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Hyannis’ place among Nebraska’s.
Hyannis weather by month
Highs, lows and precipitation from NOAA’s grid at Hyannis’ center. 1991–2020 normals.
| Month | High | Low | Rain + melt | 30-yr range |
|---|---|---|---|---|
| January | 37° | 13° | 0.4" | 18° – 36° |
| February | 40° | 16° | 0.6" | 16° – 37° |
| March | 50° | 24° | 1.1" | 28° – 47° |
| April | 58° | 32° | 2.4" | 39° – 50° |
| May | 68° | 42° | 3.3" | 48° – 60° |
| June | 80° | 52° | 3.5" | 61° – 72° |
| July | 86° | 58° | 3.2" | 66° – 78° |
| August | 85° | 56° | 2.4" | 65° – 75° |
| September | 76° | 46° | 1.7" | 54° – 67° |
| October | 62° | 34° | 1.5" | 39° – 54° |
| November | 48° | 22° | 0.6" | 25° – 43° |
| December | 38° | 15° | 0.4" | 17° – 32° |
| Year | 61° | 34° | 20.9" |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 16° to 37°. August is the most reliable, staying within 10°.
Where Hyannis’ numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Hyannis’ center.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Whitman 5 Ene, NE, 17 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Hyannis’ climate
What is the weather like in Hyannis?
A typical July afternoon reaches 86°, a January night drops to 13°. Colder January nights than 89% of U.S. towns; hotter July afternoons than 58% of U.S. towns.
How cold does it get in Hyannis in winter?
January nights average 13°. About 153 nights a year reach 32° or below and 11 reach 0° or below. In the coldest January of the last 30 years the month averaged 18°.
How hot does it get in Hyannis?
July, with a typical high of 86° and a low of 58°. About 24 days a year reach 90° and 1 reach 100° (Whitman 5 Ene, NE).
When is the first and last frost in Hyannis?
In half of years the last spring frost (32°) comes by May 4 and the first fall frost by October 8, about 155 frost-free days, at Whitman 5 Ene, NE.
What growing zone is Hyannis in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −16°.
What is the best time of year to visit Hyannis?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Hyannis getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 55% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Hyannis.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.