Best time to visit Helensburgh
Month-by-month weather averages for Helensburgh.
Helensburgh, Scotland, United Kingdom
°C
mm
- Average daily high and low
- Precipitation
- Good month
- Best month
- Made good or best by an event
| Month | Average daily high | Average daily low | Precipitation | Verdict |
|---|---|---|---|---|
| January | 6 °C / 43 °F | 1.7 °C / 35 °F | 165 mm / 6.5 in | neither best nor good |
| February | 6.9 °C / 44 °F | 2.1 °C / 36 °F | 149 mm / 5.9 in | neither best nor good |
| March | 8.5 °C / 47 °F | 2.5 °C / 37 °F | 127 mm / 5 in | neither best nor good |
| April | 11.3 °C / 52 °F | 3.9 °C / 39 °F | 88 mm / 3.4 in | neither best nor good |
| May | 14.2 °C / 58 °F | 6.8 °C / 44 °F | 117 mm / 4.6 in | neither best nor good |
| June | 16.5 °C / 62 °F | 9.7 °C / 49 °F | 112 mm / 4.4 in | good month |
| July | 17.6 °C / 64 °F | 11.3 °C / 52 °F | 137 mm / 5.4 in | good month |
| August | 17.1 °C / 63 °F | 11 °C / 52 °F | 165 mm / 6.5 in | neither best nor good |
| September | 15.4 °C / 60 °F | 9.3 °C / 49 °F | 133 mm / 5.2 in | neither best nor good |
| October | 12.3 °C / 54 °F | 6.9 °C / 44 °F | 182 mm / 7.2 in | neither best nor good |
| November | 8.7 °C / 48 °F | 3.8 °C / 39 °F | 165 mm / 6.5 in | neither best nor good |
| December | 6.5 °C / 44 °F | 2 °C / 36 °F | 187 mm / 7.4 in | neither best nor good |
Good and best months depend on more than temperature, rain and events. How they are chosen
Each activity on this page has its own good and best months, rated on twenty years of daily weather records. Which measures count, and how much, depends on the activity: humidity for exploring outdoors, wind for the beach, hiking and skiing, snow for skiing alone. Between them, the activities are rated on:
- Daytime highs
- Night-time lows
- How warm it feels
- Humidity
- How much of the day is sunny
- Hours of daylight
- Monthly rainfall
- How many days it rains
- Days of heavy rain
- Wind
- Snowfall and days with snow
- Major events, such as festivals
The chart shows the good and best months for exploring outdoors.
The event icon marks a month that an event lifts to good or best, such as a festival or a natural spectacle. Choose “Weather only” in the toolbar to rate the months on weather alone.
Best months by activity
Exploring outdoors
Mild days and nights, mostly dry and bright. The default for 'when should I go'.
- JJanuary: neither
- FFebruary: neither
- MMarch: neither
- AApril: neither
- MMay: neither
- JJune: good
- JJuly: good
- AAugust: neither
- SSeptember: neither
- OOctober: neither
- NNovember: neither
- DDecember: neither
- Good
- June–July
Why these months
June · good
In its favour: feels like (high) 15.1 °C / 59 °F, share of daylight that is sunny 60%, average daily high 16.5 °C / 62 °F, precipitation 112 mm / 4.4 in, average daily low 9.7 °C / 49 °F, days with heavy rain 3.8 days.
Against: wet days 16.1 days, relative humidity 81%.
July · good
In its favour: feels like (high) 16.8 °C / 62 °F, share of daylight that is sunny 60%, average daily high 17.6 °C / 64 °F, average daily low 11.3 °C / 52 °F.
Against: wet days 18.1 days, precipitation 137 mm / 5.4 in, days with heavy rain 5.2 days, relative humidity 84%.
Beach and swimming
Hot, dry and sunny. Penalises the monsoon hard.
- JJanuary: neither
- FFebruary: neither
- MMarch: neither
- AApril: neither
- MMay: neither
- JJune: neither
- JJuly: neither
- AAugust: neither
- SSeptember: neither
- OOctober: neither
- NNovember: neither
- DDecember: neither
No month is good for this in Helensburgh.
Hiking and trekking
Cool enough to climb in, dry enough to enjoy, long enough days.
- JJanuary: neither
- FFebruary: neither
- MMarch: neither
- AApril: best
- MMay: good
- JJune: good
- JJuly: neither
- AAugust: neither
- SSeptember: good
- OOctober: neither
- NNovember: neither
- DDecember: neither
- Best
- April
- Good
- May–June, September
Why these months
April · best
In its favour: average daily high 11.3 °C / 52 °F, precipitation 88 mm / 3.4 in, days with heavy rain 2.3 days, share of daylight that is sunny 67%, daylight per day 14.2 h, average daily low 3.9 °C / 39 °F, feels like (high) 8 °C / 46 °F, wind (daily max) 19 km/h / 12 mph.
Against: wet days 13.9 days.
May · good
In its favour: average daily high 14.2 °C / 58 °F, precipitation 117 mm / 4.6 in, feels like (high) 11.9 °C / 53 °F, average daily low 6.8 °C / 44 °F, share of daylight that is sunny 65%, daylight per day 16.3 h, days with heavy rain 4 days, wind (daily max) 18 km/h / 11 mph.
Against: wet days 16.8 days.
June · good
In its favour: average daily high 16.5 °C / 62 °F, precipitation 112 mm / 4.4 in, feels like (high) 15.1 °C / 59 °F, average daily low 9.7 °C / 49 °F, share of daylight that is sunny 60%, daylight per day 17.5 h, days with heavy rain 3.8 days, wind (daily max) 17 km/h / 10 mph.
Against: wet days 16.1 days.
September · good
In its favour: average daily high 15.4 °C / 60 °F, feels like (high) 13.7 °C / 57 °F, average daily low 9.3 °C / 49 °F, share of daylight that is sunny 56%, daylight per day 12.7 h, precipitation 133 mm / 5.2 in, wind (daily max) 18 km/h / 11 mph.
Against: wet days 16.2 days, days with heavy rain 4.6 days.
An activity is listed only where it applies: skiing at ski destinations, beach and swimming at beach destinations. The nearest ski area is Glencoe Mountain Resort, 68 km away.
Weather averages
Monthly averages over twenty years, 2006–2025. Highs, lows and precipitation are in the chart at the top.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels like (high) | 2.5 °C | 3.1 °C | 4.7 °C | 8 °C | 11.9 °C | 15.1 °C | 16.8 °C | 15.9 °C | 13.7 °C | 9.9 °C | 5.8 °C | 3.1 °C |
| Days with heavy rain | 7 days | 5.8 days | 4.7 days | 2.3 days | 4 days | 3.8 days | 5.2 days | 5.8 days | 4.6 days | 7.2 days | 6.3 days | 7.3 days |
| Time rain usually falls | 3 pm | 3 pm | 5 pm | 5 pm | 5 pm | 5 pm | 4 pm | 3 pm | 4 pm | 3 pm | 4 pm | 8 pm |
| Sunshine per day | 3.2 h | 4.9 h | 6.9 h | 9.6 h | 10.7 h | 10.6 h | 10.2 h | 9.1 h | 7.1 h | 5.1 h | 3.8 h | 2.6 h |
| Relative humidity | 89% | 87% | 83% | 79% | 78% | 81% | 84% | 85% | 86% | 88% | 89% | 90% |
Sea temperature
Averaged over a shorter period (2022–2025) than the twenty-year averages above.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature 2022–2025 | 8.4 °C | 8 °C | 8.6 °C | 10.1 °C | 12.4 °C | 13.8 °C | 15.2 °C | 15.7 °C | 15 °C | 13.5 °C | 11.8 °C | 9.8 °C |
| Sea temperature (daily max) 2022–2025 | 8.5 °C | 8.1 °C | 8.7 °C | 10.3 °C | 12.8 °C | 14.2 °C | 15.5 °C | 15.9 °C | 15.2 °C | 13.6 °C | 11.9 °C | 9.8 °C |
- Very cold 10 °C or less
- Cold 10 to 15 °C
- Cool 15 to 20 °C
- Comfortable 20 to 25 °C
- Warm 25 to 28 °C
- Very warm over 28 °C
The words describe how the water feels to swim in. They are ours, not an official standard.
Air quality
Averaged over a shorter period (2022–2025) than the twenty-year averages above, and not counted towards good or best months.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Air pollution (PM2.5) 2022–2025 | 4.6 µg/m³ | 5.3 µg/m³ | 5.6 µg/m³ | 6.7 µg/m³ | 7.7 µg/m³ | 7.5 µg/m³ | 5.1 µg/m³ | 6.1 µg/m³ | 5.2 µg/m³ | 5 µg/m³ | 4.1 µg/m³ | 4.4 µg/m³ |
| Air pollution (PM2.5, daily peak) 2022–2025 | 8.2 µg/m³ | 9.6 µg/m³ | 9.9 µg/m³ | 12.3 µg/m³ | 13.6 µg/m³ | 12.6 µg/m³ | 9.3 µg/m³ | 10 µg/m³ | 8.4 µg/m³ | 8.6 µg/m³ | 7.7 µg/m³ | 7.9 µg/m³ |
- Good 15 µg/m³ or less
- Fair 15 to 25 µg/m³
- Moderate 25 to 37.5 µg/m³
- Poor 37.5 to 50 µg/m³
- Very poor 50 to 75 µg/m³
- Extremely poor over 75 µg/m³
Each figure is compared with the World Health Organization's guideline for a day's air, 15 µg/m³ or less, and with its interim targets above that. The words are ours: the WHO does not name its steps. The figures are modelled monthly averages, so single days can be well above them. The daily peak is the average of each day's highest hour, shaded on the same scale.