Climate and average weather in Newton

In Newton, the summers are humid, hot, showery, and partly cloudy and the winters are very cold, snowy, and partly cloudy.

Best: mid May to mid October

Over the course of the year, the temperature in Newton typically varies from 13°F to 83°F, and is rarely below -7°F or above 92°F. July is the hottest month of the year, while January is the coldest.

Based on the travel score, the best time of year to visit Newton for warm-weather activities is from mid May to mid October.

Hottest
Jul
83°
Coldest
Jan
13°
Wettest
May
5.4 in
Driest
Jan
1.3 in
Rain / yr
38.9 in
108 wet days
Daylight
9.0–15.0 h
shortest–longest
Elevation
951 ft
41.7°N
Clearest
Sep
46% cloud

Newton is city in and the county seat of Jasper County, Iowa, United States.

Density
519/km²
people per km²
Founded
1850

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Newton weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around mid May to mid October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Newton, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 4.6 months, from May 13 to September 29, with daily high temperatures above 70°F. The hottest month of the year in Newton is July, with an average high of 83°F and low of 65°F.

The cool season lasts 3.0 months, from December 2 to March 2, with daily high temperatures below 39°F. The coldest month of the year in Newton is January, with an average low of 13°F and high of 29°F.

Days typically run about 18°F warmer than nights year-round.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)Avg low (°F)
Jan2913
Feb3417
Mar4729
Apr6040
May7152
Jun8062
Jul8365
Aug8163
Sep7555
Oct6242
Nov4730
Dec3419

How hot and cold Newton really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the coldest nights, wind chill pulls the feels-like down to about -0°F (around January 17), with roughly 168 freezing days a year (feels-like at or below 32°F) 97 of them bitterly cold — worst in January.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°F)Air high (°F)Feels-like low (°F)Air low (°F)
Jan2929113
Feb3434517
Mar47471929
Apr60603440
May71715152
Jun80806262
Jul85836565
Aug82816363
Sep75755455
Oct62623742
Nov47472130
Dec3434819

Average hourly temperature in Newton

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on July afternoons, near 83°F, and coldest before dawn in January, near 13°F.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Newton weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan29° / 13°1.36.64.89.30.0
Feb34° / 17°1.66.64.710.30.0
Mar47° / 29°2.78.82.711.71.6
Apr60° / 40°4.411.2113.14.7
May71° / 52°5.413.50.114.36.0
Jun80° / 62°5.211.60156.3
Jul83° / 65°3.910014.76.0
Aug81° / 63°4.09.4013.76.7
Sep75° / 55°3.88.3012.37.2
Oct62° / 42°2.98.30.410.95.5
Nov47° / 30°2.26.91.69.61.7
Dec34° / 19°1.66.44.390.0

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Newton gets about 38.9 in of precipitation a year. On a typical day the chance of rain is some rain, but that rises and falls sharply with the seasons.

The wetter season lasts 5.0 months, from around Mar 22 to Aug 21, peaking in May at about 46% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jan 30.

May is the wettest month by volume, with 5.4 in over about 14 wet days; January is the driest, with 1.3 in. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%60%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetMay 29 · 46%Jan 30 · 21%
Rain on a day (%)Rain days
Jan217
Feb237
Mar289
Apr3811
May4314
Jun3912
Jul3310
Aug309
Sep288
Oct278
Nov237
Dec216

Monthly rainfall

Over a full year, Newton collects about 38.9 in of rain across 108 wet days — roughly 3.2 in in an average month.

It doesn’t fall evenly. May is the wettest month with 5.4 in, while January is the driest at just 1.3 in. The three wettest months alone bring about 39% of the year’s total, and some of the cold-season precipitation falls as snow.

01234567JanFebMarAprMayJunJulAugSepOctNovDec1.31.62.74.45.45.23.94.03.82.92.21.6
Rainfall (in)Rain daysSnow days
Jan1.375
Feb1.675
Mar2.793
Apr4.4111
May5.4140
Jun5.2120
Jul3.9100
Aug4.090
Sep3.880
Oct2.980
Nov2.272
Dec1.664

Snow in Newton

Average snowy days through the year, the snow-season span, and estimated snowfall — for ski trips and the perennial 'will there be snow at Christmas?' question.

Newton averages about 20 snowy days a year. Snow season runs roughly Oct 22 to Apr 25 — about 6.1 months.

February is snowiest, with roughly 5 days of snow and an estimated 10 in of snowfall. Over the year that adds up to an estimated 37 in of snow.

02468JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonFeb 9
Snow daysSnowfall (in)
Jan59
Feb510
Mar35
Apr13
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov22
Dec47

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Newton, the average share of the sky covered by clouds shows moderate seasonal variation over the course of the year.

The clearer part of the year begins around June 2 and lasts for 5.5 months, ending around November 14. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 61% of the time on average.

The cloudier part of the year begins around November 15 and lasts for 6.5 months, ending around June 1. The cloudiest month is January, when it is overcast or mostly cloudy 62% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecSep 2 · 65%Jan 29 · 38%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan3862
Feb4159
Mar4357
Apr3961
May4357
Jun5149
Jul5941
Aug6139
Sep6040
Oct5446
Nov4654
Dec3961

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 11, brings about 15 hours of light; the shortest, around January 1, only 9 hours — a swing of roughly 6 hours.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.37:435:00
Feb10.37:175:37
Mar11.76:326:11
Apr13.15:396:46
May14.34:587:19
Jun15.04:427:43
Jul14.74:557:40
Aug13.75:257:07
Sep12.35:586:15
Oct10.96:325:23
Nov9.67:094:46
Dec9.07:394:38

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Newton averages about 10 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 8 and 15 days.

The sunnier stretch runs 5.1 months, from around Jun 18 to Nov 19. The sunniest month is September, with roughly 14 sunny days (mixed).

The greyest month is May, down near 8 sunny days — about 43% fewer than the September peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightSep 315 daysMay 88 days
Sunny daysSky
Jan8Gloomy
Feb8Mixed
Mar9Mixed
Apr8Mixed
May8Mixed
Jun10Mixed
Jul12Mixed
Aug13Mixed
Sep14Mixed
Oct13Mixed
Nov10Mixed
Dec8Mixed

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In Newton, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 4.0 months, from around May 22 to September 20. The muggiest month is July, when the air feels humid, muggy or worse about 78% of the time.

The most comfortable stretch runs from around September 21 to May 21, and March is the most comfortable month — the air is dry or comfortable 100% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecMar 6 · 100%Jul 17 · 18%oppressivemuggydryhumidcomfortablecomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan10000000
Feb10000000
Mar9820000
Apr9551000
May681512500
Jun2322232570
Jul6162530212
Aug12192628131
Sep5120141220
Oct8973100
Nov9910000
Dec10000000

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Newton is typically light breeze, near 9 mph, and varies moderately with the seasons.

The windier part of the year lasts 7.9 months, from around Sep 27 to May 23. The windiest month is April, averaging about 10 mph (light breeze).

The calmer part of the year runs from around May 24 to Sep 26, with August the calmest month at about 7 mph.

051015JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezebreezyApr 11 · 11 mphAug 5 · 7 mph
Wind speed (mph)Feels
Jan10light breeze
Feb10light breeze
Mar10light breeze
Apr10light breeze
May9light breeze
Jun8light breeze
Jul7calm
Aug7calm
Sep9light breeze
Oct10light breeze
Nov10light breeze
Dec9light breeze

Best time to visit Newton

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Newton throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around mid May, Newton is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 64°F and 82°F. Based on this score, the best time of year to visit Newton for general outdoor tourist activities is from mid May to mid October, with a peak score in the second week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationSep 8 · 7.3

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan0.0poor
Feb0.0poor
Mar1.7poor
Apr4.6fair
May6.0good
Jun6.3good
Jul6.0good
Aug6.7good
Sep7.2good
Oct5.5fair
Nov1.7poor
Dec0.0poor

The beach/pool score favors clear, rainless days with daytime highs between 75°F and 93°F. Based on this score, the best time of year to visit Newton for hot-weather activities is from early June to mid September, with a peak score in the third week of July.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationJul 20 · 7.1

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Newton, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around July (highs near 83°F), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 29°F), pack a warm layer and a heavy coat.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Newton sees daytime highs around 83°F and nights near 65°F. Pack light clothes and sun protection. Worth having: rain gear. About 10 days see rain.

UV index (midday) in Newton by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Newton peaks around June 19 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJun 19UV 9Dec 21UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May7Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep6High
Oct4Moderate
Nov3Moderate
Dec2Low

Average hourly UV index in Newton

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in June the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 5.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan00
Feb00
Mar40
Apr6.50
May7.53.5
Jun8.55.5
Jul8.55
Aug7.54
Sep60.5
Oct3.50
Nov00
Dec00

Air quality in Newton by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.

Air quality in Newton is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 7 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateGoodJul 1916 µg/m³Oct 218 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb15Moderate
Mar14Moderate
Apr11Good
May12Good
Jun13Moderate
Jul16Moderate
Aug15Moderate
Sep12Good
Oct7Good
Nov9Good
Dec10Good
Almanac & agriculture

Growing season

Chance of a frost-free dayTypical season (≥50%)

The growing season in Newton typically lasts about 233 days, from around March 23 to November 10 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 22 to October 12.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonFeb 310%Mar 2350%Apr 2290%Oct 1290%Nov 1050%Jan 810%
Frost-free chance (%)Frost nights
Jan931
Feb1428
Mar3931
Apr8120
May990
Jun1000
Jul1000
Aug1000
Sep990
Oct8618
Nov4330
Dec1531

Growing degree days

Degree days (base 50°F)Frost-free shaded

Growing degree days tally heat above 50°F: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Newton banks about 2,984 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

01,0002,0003,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°F·days)
Jan0
Feb0
Mar0
Apr46
May353
Jun627
Jul751
Aug678
Sep437
Oct92
Nov0
Dec0

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Newton receives about 4.2 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 1.8 and 6.6 kWh/m².

The brighter stretch of the year lasts 6.3 months, from around Mar 16 to Sep 23. The brightest month is July, averaging about 6.4 kWh/m² (intense).

The dimmest month is December, down near 1.8 kWh/m² — roughly 72% less than the July peak.

012345678JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJul 26.6 kWhDec 201.8 kWh
Solar energy (kWh/m²)Level
Jan2.1Moderate
Feb3.2Moderate
Mar4.2Bright
Apr5.0Bright
May5.7Bright
Jun6.4Intense
Jul6.5Intense
Aug5.6Bright
Sep4.6Bright
Oct3.2Moderate
Nov2.2Moderate
Dec1.8Dim

Where is Newton?

Newton sits at 41.7°N, 93.0°W, 951 ft above sea level, in United States. The nearest listed city is Altoona, 22 mi away.

Topography around Newton

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Newton.

Within 2 miles, the terrain around Newton has only modest variations in elevation — a maximum elevation change of 200 ft around an average of 922 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 282 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 587 ft.

The land around Newton is covered by grassland (28%), cropland (26%) and trees (25%) within 2 miles, cropland (73%) within 10 miles, and cropland (68%) within 50 miles.

2 miles
200 ft
10 miles
282 ft
50 miles
587 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
Nearby: Altoona 22 mi · Marshalltown 25 mi · Ankeny 29 mi · Des Moines 30 mi · Johnston 34 mi · Urbandale 35 mi · West Des Moines 35 mi · Indianola 35 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Newton (41.6997°, -93.048°, elevation 951 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).