Castlereagh in Fall
In fall (September, October and November), Castlereagh sees average daytime highs around 13°C and overnight lows near 8°C, with 241 mm of precipitation over about 40 wet days across the season. It is the 2nd-warmest season and the wettest season of the year.
Over the season highs ease from about 17°C in early September to 9°C by late November. The sky is clear or mostly clear about 10% of the time across fall, and the air most often feels dry.
Fall is Castlereagh's 2nd-best season to visit on our travel score. For the whole year in context, see Castlereagh's year-round climate.
- Avg daytime high
- 13°C
- 2nd-warmest season
- Avg overnight low
- 8°C
- Precipitation
- 241 mm
- 40 wet days
- Avg wind
- 17 km/h
- Travel score
- 3.1
- 2nd-best season
- Months
- Sep · Oct · Nov
Temperature in Castlereagh in Fall
Over the season highs ease from about 17°C in early September to 9°C by late November.
A typical fall day in Castlereagh reaches about 13°C and drops to 8°C overnight. The warmest of the three months is September, the coolest November.
How fall really feels in Castlereagh
Once humidity and wind are folded in, fall brings about 0 days that feel above 32°C and 0 that feel at or below 0°C.
fall sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Castlereagh weather by month
How the three fall months (September, October and November) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 7° / 4° | 77 | 14.2 | 0.8 | 7.6 | 1.0 |
| Feb | 8° / 4° | 62 | 12.1 | 0.9 | 9.3 | 1.1 |
| Mar | 9° / 4° | 62 | 13.4 | 0.6 | 11.5 | 1.6 |
| Apr | 11° / 6° | 65 | 13 | 0.2 | 13.7 | 2.5 |
| May | 14° / 8° | 70 | 14.1 | 0.1 | 15.8 | 3.5 |
| Jun | 16° / 11° | 75 | 13.2 | 0 | 16.9 | 4.4 |
| Jul | 18° / 12° | 81 | 14.6 | 0 | 16.4 | 4.9 |
| Aug | 18° / 12° | 81 | 14.2 | 0 | 14.7 | 4.9 |
| Sep | 16° / 11° | 70 | 12.5 | 0 | 12.5 | 4.4 |
| Oct | 13° / 8° | 87 | 13.5 | 0 | 10.2 | 3.1 |
| Nov | 10° / 6° | 85 | 14 | 0.2 | 8.2 | 1.9 |
| Dec | 8° / 4° | 82 | 13.5 | 0.5 | 7.1 | 1.2 |
Cloud cover in Fall
The sky is clear or mostly clear about 10% of the time across fall.
Chance of precipitation in Fall
Castlereagh gets around 241 mm of rain and snow over 40 wet days across fall. The line is the day-by-day chance of measurable precipitation.
Humidity in Fall
Most of fall feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Fall
Winds average 17 km/h across fall.
Sunrise & sunset in Fall
Daylight runs from about 13 h 36 min in early September to 7 h 24 min by late November. The lit band spans sunrise to sunset each day.
Solar energy in Fall
Average shortwave solar energy reaching the ground each day across fall, about 1.7 kWh/m².
Is fall a good time to visit Castlereagh?
Our two travel scores rate fall for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
fall is a weaker month for outdoor sightseeing in Castlereagh.
What to pack for Castlereagh in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, Castlereagh sees daytime highs around 13°C and nights near 8°C. Pack a warm layer and rain gear. About 40 days see rain.
Sea temperature near Castlereagh in Fall
The nearest coast averages about 13°C across fall — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 33 km away) is warmest in August at about 14°C and coldest in March near 8°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) | 9 | 8 | 8 | 8 | 10 | 12 | 13 | 14 | 14 | 14 | 12 | 11 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 9 | Bracing |
| Feb | 8 | Bracing |
| Mar | 8 | Bracing |
| Apr | 8 | Bracing |
| May | 10 | Bracing |
| Jun | 12 | Bracing |
| Jul | 13 | Bracing |
| Aug | 14 | Bracing |
| Sep | 14 | Bracing |
| Oct | 14 | Bracing |
| Nov | 12 | Bracing |
| Dec | 11 | Bracing |
UV index in Castlereagh in Fall
Clear-sky midday UV across fall averages around 2. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Castlereagh peaks around July 24 at about 5 (high) — a little sun protection helps at midday. It bottoms out near January 1 at about 0 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 5 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 0 | 1 | 2 | 3 | 5 | 5 | 5 | 5 | 3 | 2 | 1 | 0 |
| Level | Low | Low | Moderate | Moderate | High | High | High | High | Moderate | Low | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 0 | Low |
| Feb | 1 | Low |
| Mar | 2 | Moderate |
| Apr | 3 | Moderate |
| May | 5 | High |
| Jun | 5 | High |
| Jul | 5 | High |
| Aug | 5 | High |
| Sep | 3 | Moderate |
| Oct | 2 | Low |
| Nov | 1 | Low |
| Dec | 0 | Low |
Where is Castlereagh?
Castlereagh sits at 54.6°N, 5.9°W, 29 m above sea level, in United Kingdom. The nearest listed city is Belfast, 4.0 km away.
Topography around Castlereagh
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Castlereagh.
Within 3 km, the terrain around Castlereagh has only modest variations in elevation — a maximum elevation change of 178 m around an average of 61 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 495 m; within 80 km, large variations in elevation — a maximum elevation change of 860 m.
The land around Castlereagh is covered by artificial surfaces (41%), grassland (32%) and trees (24%) within 3 km, grassland (55%) within 16 km, and water (47%) and grassland (46%) within 80 km.
United Kingdom travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type D / G / M
- 230 V · 50 Hz
- Prices
- ≈ 89% of US
- price level, 2025
- GDP per capita
- $57,602
- 2025
- Happiness
- 6.7 / 10
- World Happiness, 2025
- Safe drinking water
- 100%
- of population, 2024
- Homicide rate
- 1.1
- per 100k, 2021
- Road deaths
- 3.2
- 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 Castlereagh (54.5735°, -5.8847°, elevation 29 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.