Bethlehem has chilly winters and pleasant summers, with plenty of rain. A typical July afternoon reaches 84°, a January night drops to 19°, and about 23 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normalsUpdated once a decade
☀️
July high
84°
118th coolest of 941 New Jersey towns
❄️
January low
19°
116th coldest of 941 New Jersey towns
💧
Rain + melted snow
50 in
37th wettest of 941 New Jersey towns
🌨️
Snow a winter
23 in
393rd least snowy of 898 New Jersey towns
A normal year
What a year in Bethlehem feels like
❄️
Winter
40° / 22°
Typical high / low · 7 days with an inch or more of snow
🌷
Spring
60° / 38°
Typical high / low · Last frost around Apr 30
☀️
Summer
82° / 60°
Typical high / low · 14 days reach 90° in a normal year
🍂
Fall
64° / 43°
Typical high / low · First frost around Oct 18
10°
20°
40°
50°
60°
70°
80°
90°
100°
32°
37°
19°
40°
21°
49°
28°
61°
38°
71°
48°
79°
57°
84°
62°
82°
60°
75°
53°
64°
42°
52°
33°
42°
25°
JanJFebFMarMAprAMayMJunJJulJAugASepSOctONovNDecD
32°, freezingBar runs from the typical overnight low up to the afternoon high
Best months to be outsideMayJunJulAugSepOctHighs of 62–84° and lows of 40° or more
Month by month
Bethlehem weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
Month
High
Low
Rain + melt
Snow
Wet days
30-yr range
January
37°
19°
3.6"
9.9"
11
19° – 36°
February
40°
21°
2.8"
5.2"
9
19° – 37°
March
49°
28°
3.9"
3.5"
11
32° – 48°
April
61°
38°
4.0"
0.3"
11
45° – 54°
May
71°
48°
4.2"
0
14
55° – 65°
June
79°
57°
4.6"
0
12
64° – 71°
July
84°
62°
5.1"
0
11
68° – 77°
August
82°
60°
4.8"
0
11
67° – 74°
September
75°
53°
4.6"
0
9
61° – 68°
October
64°
42°
4.6"
0
10
48° – 60°
November
52°
33°
3.4"
0.4"
10
38° – 47°
December
42°
25°
4.4"
4.0"
12
26° – 44°
Year
61°
40°
50.0"
23.3"
131
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain & snow
Rain and snow in Bethlehem
Bethlehem gets 50 inches of rain and melted snow a year. July is the wettest month and February the driest. Rain or snow falls on about 131 days a year.
💧
50 in
Rain + melted snow a year
More rain than 87% of U.S. towns
❄️
23 in
Snow in a normal winter
Less snow than 53% of U.S. towns
☔
131 days
With rain or snow (0.01"+)
Rain + melted snow by month
Inches of water
5.1"
JFMAMJJASOND
Snowfall by month
Inches of snow
9.9"
JFMAMJJASOND
Frost & the growing season
About 168 frost-free days a year
In half of years the last 32° night comes by April 30 and the first one by October 18. That leaves about 168 frost-free days for gardens, shorter than 63% of U.S. towns.
🌱 Apr 30
🍂 Oct 18
168 frost-free days
JFMAMJJASOND
🥶
135
nights at or below 32° in a normal year
🧊
2
nights below 0° in a normal year
🔥
14
days that reach 90° in a normal year
Freezing nights by month
Average nights at or below 32°
JFMAMJJASOND
90° days by month
Average days at 90° or more
JFMAMJJASOND
Heating & cooling
Heating and cooling a home in Bethlehem
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Bethlehem, 90% of that work is heating and 10% is cooling, so the furnace matters far more than the air conditioner.
🔥
6,050 heating degree daysMore heating than 57% of U.S. towns
❄️
650 cooling degree daysLess cooling than 65% of U.S. towns
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Around Bethlehem
Bethlehem and its neighbors
Bethlehem borders 10 towns with climate data. January nights across them vary by 1.0°. Lebanon has the coldest January nights (19°) and Pohatcong the hottest July afternoons (86°). Bethlehem’s January low is 19° and its July high 84°.
Compared with every U.S. town and city on TownTapestry, each counted once.
Then and now
Warmer than it used to be
+2.3°1991–2020 average vs. the 20th century (1901–2000)
The last 30 years in Bethlehem averaged 2.3° warmer than the 1900s. The biggest change is in December (+4.1°). The shift is larger than in 99% of U.S. towns.
❄️ Winter+3.4°now 31°, was 27°
🌷 Spring+2.0°now 49°, was 47°
☀️ Summer+1.8°now 71°, was 69°
🍂 Fall+2.1°now 53°, was 51°
Change by month1991–2020 average minus 1901–2000 average, at Bethlehem’s spot on NOAA’s grid
+1.6°
+4.1°
JanJFebFMarMAprAMayMJunJJulJAugASepSOctONovNDecD
Year to year
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 19° to 37°. June is the most reliable, staying within 7°.
10°
20°
30°
40°
50°
60°
70°
80°
90°
JanJFebFMarMAprAMayMJunJJulJAugASepSOctONovNDecD
Coldest to warmest month in 30 yearsNormal
Questions
Common questions about Bethlehem’s climate
What is the coldest month in Bethlehem?
January, with a typical high of 37° and a low of 19°.
What is the hottest month in Bethlehem?
July, with a typical high of 84° and a low of 62°. About 14 days a year reach 90°.
How much snow does Bethlehem get?
About 23 inches in a normal winter, most of it in January.
When is the first frost in Bethlehem?
In half of years the first 32° night comes by October 18, and the last spring frost by April 30.
What is the rainiest month in Bethlehem?
July, with 5.1 inches of rain and melted snow. The year totals 50 inches.
📍Temperatures and rainfall come from NOAA’s gridded climate normals for Bethlehem itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Belvidere Brg, NJ (12 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.