Climate and average weather in Whanganui
In Whanganui, the summers are mild, showery, and partly cloudy and the winters are cool, breezy, and partly cloudy.
Over the course of the year, the temperature in Whanganui typically varies from 9°C to 20°C, and is rarely below 6°C or above 22°C. February is the hottest month of the year, while July is the coldest.
Based on the travel score, the best times of year to visit Whanganui for warm-weather activities are from early January to late April and mid December to late December.
- Hottest
- Feb
- 20°
- Coldest
- Jul
- 9°
- Wettest
- Jun
- 109 mm
- Driest
- Feb
- 66 mm
- Rain / yr
- 1110 mm
- 146 wet days
- Daylight
- 9.2–14.8 h
- shortest–longest
- Elevation
- 18 m
- 39.9°S
- Clearest
- Feb
- 51% cloud
Whanganui is city in New Zealand's North Island.
- Density
- 20,736/km²
- people per km²
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Whanganui 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 early January to late April.
Temperature through the year
Daily average highs and lows in Whanganui, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
Temperatures in Whanganui stay fairly even through the year, without a distinct hot or cool season. The warmest month is February, with an average high of 20°C and low of 16°C; the coolest is July, with an average low of 9°C and high of 12°C.
Days typically run about 3°C warmer than nights year-round.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 19 | 20 | 18 | 17 | 15 | 13 | 12 | 12 | 13 | 14 | 16 | 17 |
| Avg low (°C) | 15 | 16 | 15 | 13 | 11 | 10 | 9 | 9 | 10 | 11 | 12 | 14 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| Jan | 19 | 15 |
| Feb | 20 | 16 |
| Mar | 18 | 15 |
| Apr | 17 | 13 |
| May | 15 | 11 |
| Jun | 13 | 10 |
| Jul | 12 | 9 |
| Aug | 12 | 9 |
| Sep | 13 | 10 |
| Oct | 14 | 11 |
| Nov | 16 | 12 |
| Dec | 17 | 14 |
Average hourly temperature in Whanganui
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 February afternoons, near 20°C, and coldest before dawn in July, near 9°C.
Whanganui weather by month
Every month at a glance. Click a month for its detailed page.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 19° / 15° | 71 | 9.3 | 14.5 | 6.3 |
| Feb | 20° / 16° | 66 | 8.1 | 13.6 | 6.5 |
| Mar | 18° / 15° | 68 | 9.6 | 12.3 | 6.2 |
| Apr | 17° / 13° | 98 | 11 | 11 | 5.2 |
| May | 15° / 11° | 97 | 12.4 | 9.8 | 4.3 |
| Jun | 13° / 10° | 109 | 14.1 | 9.2 | 3.2 |
| Jul | 12° / 9° | 105 | 14.3 | 9.5 | 2.9 |
| Aug | 12° / 9° | 102 | 14.7 | 10.4 | 3.0 |
| Sep | 13° / 10° | 97 | 13.6 | 11.7 | 3.4 |
| Oct | 14° / 11° | 107 | 14.2 | 13.1 | 3.8 |
| Nov | 16° / 12° | 89 | 12.2 | 14.2 | 4.6 |
| Dec | 17° / 14° | 100 | 12.7 | 14.8 | 5.4 |
Chance of rain
How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.
Whanganui gets about 1110 mm of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.
The wetter season lasts 6.0 months, from around May 16 to Nov 14, peaking in August at about 49% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Mar 2.
June is the wettest month by volume, with 109 mm over about 14 wet days; February is the driest, with 66 mm.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 31 | 29 | 31 | 36 | 40 | 47 | 47 | 47 | 45 | 46 | 41 | 40 |
| Rain days | 9 | 8 | 10 | 11 | 12 | 14 | 14 | 15 | 14 | 14 | 12 | 13 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 31 | 9 |
| Feb | 29 | 8 |
| Mar | 31 | 10 |
| Apr | 36 | 11 |
| May | 40 | 12 |
| Jun | 47 | 14 |
| Jul | 47 | 14 |
| Aug | 47 | 15 |
| Sep | 45 | 14 |
| Oct | 46 | 14 |
| Nov | 41 | 12 |
| Dec | 40 | 13 |
Monthly rainfall
Over a full year, Whanganui collects about 1110 mm of rain across 146 wet days — roughly 92 mm in an average month.
It doesn’t fall evenly. June is the wettest month with 109 mm, while February is the driest at just 66 mm. The three wettest months alone bring about 29% of the year’s total.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 71 | 66 | 68 | 98 | 97 | 109 | 105 | 102 | 97 | 107 | 89 | 100 |
| Rain days | 9 | 8 | 10 | 11 | 12 | 14 | 14 | 15 | 14 | 14 | 12 | 13 |
| Rainfall (mm) | Rain days | |
|---|---|---|
| Jan | 71 | 9 |
| Feb | 66 | 8 |
| Mar | 68 | 10 |
| Apr | 98 | 11 |
| May | 97 | 12 |
| Jun | 109 | 14 |
| Jul | 105 | 14 |
| Aug | 102 | 15 |
| Sep | 97 | 14 |
| Oct | 107 | 14 |
| Nov | 89 | 12 |
| Dec | 100 | 13 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In Whanganui, the average share of the sky covered by clouds shows mild seasonal variation over the course of the year.
The clearer part of the year begins around December 31 and lasts for 3.0 months, ending around March 30. The clearest month is February, when the sky is clear, mostly clear, or partly cloudy 59% of the time on average.
The cloudier part of the year begins around June 1 and lasts for 2.5 months, ending around August 15. The cloudiest month is July, when it is overcast or mostly cloudy 51% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 57 | 59 | 57 | 54 | 53 | 51 | 49 | 53 | 52 | 51 | 53 | 50 |
| Cloudier (%) | 43 | 41 | 43 | 46 | 47 | 49 | 51 | 47 | 48 | 49 | 47 | 50 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 57 | 43 |
| Feb | 59 | 41 |
| Mar | 57 | 43 |
| Apr | 54 | 46 |
| May | 53 | 47 |
| Jun | 51 | 49 |
| Jul | 49 | 51 |
| Aug | 53 | 47 |
| Sep | 52 | 48 |
| Oct | 51 | 49 |
| Nov | 53 | 47 |
| Dec | 50 | 50 |
Daylight, sunrise and sunset
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 January 1, brings about 14 h 48 min of light; the shortest, around June 10, only 9 h 12 min — a swing of roughly 5 h 36 min.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 14.5 | 13.6 | 12.3 | 11.0 | 9.8 | 9.2 | 9.5 | 10.4 | 11.7 | 13.1 | 14.2 | 14.8 |
| Sunrise (AM) | 6:13 | 6:47 | 7:20 | 7:52 | 8:22 | 8:45 | 8:43 | 8:12 | 7:22 | 6:33 | 5:58 | 5:51 |
| Sunset (PM) | 8:45 | 8:21 | 7:39 | 6:48 | 6:10 | 5:56 | 6:08 | 6:36 | 7:06 | 7:37 | 8:12 | 8:41 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 14.5 | 6:13 | 8:45 |
| Feb | 13.6 | 6:47 | 8:21 |
| Mar | 12.3 | 7:20 | 7:39 |
| Apr | 11.0 | 7:52 | 6:48 |
| May | 9.8 | 8:22 | 6:10 |
| Jun | 9.2 | 8:45 | 5:56 |
| Jul | 9.5 | 8:43 | 6:08 |
| Aug | 10.4 | 8:12 | 6:36 |
| Sep | 11.7 | 7:22 | 7:06 |
| Oct | 13.1 | 6:33 | 7:37 |
| Nov | 14.2 | 5:58 | 8:12 |
| Dec | 14.8 | 5:51 | 8:41 |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
Whanganui 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 13 days.
The sunnier stretch runs 3.8 months, from around Dec 30 to Apr 23. The sunniest month is March, with roughly 12 sunny days (mixed).
The greyest month is June, down near 8 sunny days — about 29% fewer than the March peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 12 | 11 | 12 | 10 | 10 | 8 | 9 | 10 | 9 | 10 | 10 | 9 |
| Sky | Mixed | Mixed | Mixed | Mixed | Mixed | Mixed | Mixed | Mixed | Mixed | Mixed | Mixed | Mixed |
| Sunny days | Sky | |
|---|---|---|
| Jan | 12 | Mixed |
| Feb | 11 | Mixed |
| Mar | 12 | Mixed |
| Apr | 10 | Mixed |
| May | 10 | Mixed |
| Jun | 8 | Mixed |
| Jul | 9 | Mixed |
| Aug | 10 | Mixed |
| Sep | 9 | Mixed |
| Oct | 10 | Mixed |
| Nov | 10 | Mixed |
| Dec | 9 | Mixed |
Humidity comfort
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 Whanganui, how humid it feels changes noticeably over the year.
The more humid part of the year lasts 3.8 months, from around December 10 to April 4. The muggiest month is February, when the air feels humid, muggy or worse about 26% of the time.
The most comfortable stretch runs from around April 5 to December 9, and May is the most comfortable month — the air is dry or comfortable 100% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 39 | 31 | 47 | 72 | 90 | 99 | 100 | 100 | 100 | 98 | 85 | 58 |
| Comfortable (%) | 41 | 42 | 42 | 25 | 10 | 1 | 0 | 0 | 0 | 2 | 14 | 35 |
| Humid (%) | 19 | 24 | 11 | 3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 7 |
| Muggy (%) | 1 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | |
|---|---|---|---|---|
| Jan | 39 | 41 | 19 | 1 |
| Feb | 31 | 42 | 24 | 2 |
| Mar | 47 | 42 | 11 | 0 |
| Apr | 72 | 25 | 3 | 0 |
| May | 90 | 10 | 0 | 0 |
| Jun | 99 | 1 | 0 | 0 |
| Jul | 100 | 0 | 0 | 0 |
| Aug | 100 | 0 | 0 | 0 |
| Sep | 100 | 0 | 0 | 0 |
| Oct | 98 | 2 | 0 | 0 |
| Nov | 85 | 14 | 0 | 0 |
| Dec | 58 | 35 | 7 | 0 |
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 Whanganui is typically breezy, near 22 km/h, and varies moderately with the seasons.
The windier part of the year lasts 3.2 months, from around Sep 3 to Dec 8. The windiest month is October, averaging about 24 km/h (breezy).
The calmer part of the year runs from around Dec 9 to May 14, with April the calmest month at about 20 km/h.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 21 | 20 | 20 | 20 | 22 | 23 | 22 | 22 | 23 | 24 | 24 | 22 |
| Feels | breezy | light breeze | breezy | light breeze | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 21 | breezy |
| Feb | 20 | light breeze |
| Mar | 20 | breezy |
| Apr | 20 | light breeze |
| May | 22 | breezy |
| Jun | 23 | breezy |
| Jul | 22 | breezy |
| Aug | 22 | breezy |
| Sep | 23 | breezy |
| Oct | 24 | breezy |
| Nov | 24 | breezy |
| Dec | 22 | breezy |
Best time to visit Whanganui
To characterize how pleasant the weather is in Whanganui throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
Around mid April, Whanganui is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.
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 18°C and 28°C. Based on this score, the best time of year to visit Whanganui for general outdoor tourist activities is from mid December to mid April, with a peak score in the first week of February.
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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Travel score (0–10) | 6.3 | 6.5 | 6.2 | 5.3 | 4.3 | 3.3 | 2.9 | 3.0 | 3.4 | 3.8 | 4.6 | 5.4 |
| Rating | good | good | good | fair | fair | poor | poor | poor | poor | fair | fair | fair |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 6.3 | good |
| Feb | 6.5 | good |
| Mar | 6.2 | good |
| Apr | 5.3 | fair |
| May | 4.3 | fair |
| Jun | 3.3 | poor |
| Jul | 2.9 | poor |
| Aug | 3.0 | poor |
| Sep | 3.4 | poor |
| Oct | 3.8 | fair |
| Nov | 4.6 | fair |
| Dec | 5.4 | fair |
The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Whanganui for hot-weather activities is from mid January to mid March, with a peak score in the second week of February.
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 Whanganui, by month
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 February (highs near 20°C), the essentials are rain gear and sun protection. In the cold season around July (highs near 12°C), pack a warm layer, rain gear and a windbreaker.
In February, Whanganui sees daytime highs around 20°C and nights near 16°C. Worth packing: rain gear and sun protection. About 8 days see rain.
Sea temperature near Whanganui
Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.
The sea at the nearest coast (about 16 km away) is warmest in February at about 19°C and coldest in August near 13°C.
The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 18 | 19 | 18 | 17 | 16 | 14 | 13 | 13 | 13 | 14 | 15 | 16 |
| Comfort | Cool | Cool | Cool | Cool | Cool | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Cool |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 18 | Cool |
| Feb | 19 | Cool |
| Mar | 18 | Cool |
| Apr | 17 | Cool |
| May | 16 | Cool |
| Jun | 14 | Bracing |
| Jul | 13 | Bracing |
| Aug | 13 | Bracing |
| Sep | 13 | Bracing |
| Oct | 14 | Bracing |
| Nov | 15 | Bracing |
| Dec | 16 | Cool |
UV index (midday) in Whanganui by month
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 Whanganui peaks around January 12 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 17 at about 2 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 12 | 11 | 7 | 5 | 2 | 2 | 2 | 3 | 4 | 7 | 10 | 11 |
| Level | Extreme | Extreme | High | Moderate | Moderate | Low | Moderate | Moderate | Moderate | High | Very high | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 12 | Extreme |
| Feb | 11 | Extreme |
| Mar | 7 | High |
| Apr | 5 | Moderate |
| May | 2 | Moderate |
| Jun | 2 | Low |
| Jul | 2 | Moderate |
| Aug | 3 | Moderate |
| Sep | 4 | Moderate |
| Oct | 7 | High |
| Nov | 10 | Very high |
| Dec | 11 | Extreme |
Average hourly UV index in Whanganui
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 January the burn window is concentrated in the middle of the day: about 9 hours a day reach index 3 (protection recommended), and 6.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV ≥ 3 (h/day) | 9 | 8.5 | 6.5 | 4 | 0 | 0 | 0 | 1 | 4.5 | 6.5 | 8.5 | 9 |
| UV ≥ 6 (h/day) | 6.5 | 6 | 2.5 | 0 | 0 | 0 | 0 | 0 | 0 | 2.5 | 5.5 | 6.5 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 9 | 6.5 |
| Feb | 8.5 | 6 |
| Mar | 6.5 | 2.5 |
| Apr | 4 | 0 |
| May | 0 | 0 |
| Jun | 0 | 0 |
| Jul | 0 | 0 |
| Aug | 1 | 0 |
| Sep | 4.5 | 0 |
| Oct | 6.5 | 2.5 |
| Nov | 8.5 | 5.5 |
| Dec | 9 | 6.5 |
Growing season
Whanganui is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Frost-free chance (%) | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Frost nights | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Frost-free chance (%) | Frost nights | |
|---|---|---|
| Jan | 100 | 0 |
| Feb | 100 | 0 |
| Mar | 100 | 0 |
| Apr | 100 | 0 |
| May | 100 | 0 |
| Jun | 100 | 0 |
| Jul | 100 | 0 |
| Aug | 100 | 0 |
| Sep | 100 | 0 |
| Oct | 100 | 0 |
| Nov | 100 | 0 |
| Dec | 100 | 0 |
Growing degree days
Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Whanganui banks about 1,335 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around February.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Growing degree days (°C·days) | 218 | 213 | 200 | 142 | 95 | 38 | 10 | 15 | 41 | 77 | 112 | 175 |
| Growing degree days (°C·days) | |
|---|---|
| Jan | 218 |
| Feb | 213 |
| Mar | 200 |
| Apr | 142 |
| May | 95 |
| Jun | 38 |
| Jul | 10 |
| Aug | 15 |
| Sep | 41 |
| Oct | 77 |
| Nov | 112 |
| Dec | 175 |
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.
Whanganui receives about 4.2 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 1.6 and 7.2 kWh/m².
The brighter stretch of the year lasts 5.8 months, from around Sep 27 to Mar 23. The brightest month is January, averaging about 6.8 kWh/m² (intense).
The dimmest month is June, down near 1.7 kWh/m² — roughly 75% less than the January peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 7.0 | 5.8 | 4.6 | 3.1 | 2.1 | 1.6 | 1.9 | 2.7 | 3.8 | 5.0 | 6.2 | 6.5 |
| Level | Intense | Bright | Bright | Moderate | Moderate | Dim | Dim | Moderate | Moderate | Bright | Intense | Intense |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 7.0 | Intense |
| Feb | 5.8 | Bright |
| Mar | 4.6 | Bright |
| Apr | 3.1 | Moderate |
| May | 2.1 | Moderate |
| Jun | 1.6 | Dim |
| Jul | 1.9 | Dim |
| Aug | 2.7 | Moderate |
| Sep | 3.8 | Moderate |
| Oct | 5.0 | Bright |
| Nov | 6.2 | Intense |
| Dec | 6.5 | Intense |
Where is Whanganui?
Whanganui sits at 39.9°S, 175.1°E, 18 m above sea level, in New Zealand. The nearest listed city is Palmerston North, 67 km away.
Topography around Whanganui
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Whanganui.
Within 3 km, the terrain around Whanganui has only modest variations in elevation — a maximum elevation change of 103 m around an average of 28 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 300 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,746 m.
The land around Whanganui is covered by grassland (39%), artificial surfaces (28%) and trees (25%) within 3 km, grassland (42%), water (32%) and trees (22%) within 16 km, and grassland (44%), trees (29%) and water (25%) within 80 km.
New Zealand travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type I
- 230 V · 50 Hz
- Prices
- ≈ 86% of US
- price level, 2025
- GDP per capita
- $49,591
- 2025
- Happiness
- 7.0 / 10
- World Happiness, 2025
- Safe drinking water
- 100%
- of population, 2024
- Homicide rate
- 1.5
- per 100k, 2022
- Road deaths
- 9.6
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
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 Whanganui (-39.9333°, 175.05°, elevation 18 m), 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).