Vartry Reservoir Water Temperature Today
Vartry Reservoir, a flooded quarry swim site in Wicklow, Ireland. The water peaks in the high teens to low twenties in July and August, and is cold but ice-free in winter.
In August Vartry Reservoir averages about 19°C, peaking near 19°C in July, August, September and dropping to roughly 5°C at its coldest.
River and swimming-hole temperatures are modelled from long-term monthly averages and refined with live air temperature, wind and UV. Moving water reacts faster to the weather than a lake or the sea.
Vartry Reservoir water temperature by month
| Month | Average water temperature | Swimming |
|---|---|---|
| January | 5.9°C | cold |
| February | 5.0°C | cold |
| March | 5.9°C | cold |
| April | 8.5°C | cold |
| May | 12.0°C | cool |
| June | 15.5°C | mild |
| July | 18.1°C | mild |
| August | 19.0°C | mild |
| September | 18.1°C | mild |
| October | 15.5°C | mild |
| November | 12.0°C | cool |
| December | 8.5°C | cold |
Vartry Reservoir swim conditions FAQ
What is the water temperature in Vartry Reservoir right now?
In August the water in Vartry Reservoir averages about 19°C. We refine that long-term average with today's air temperature, because this flooded quarry responds quickly to the weather.
When is the best time to swim in Vartry Reservoir?
The comfortable swim season — 18°C or warmer — runs through July, August, September, with the warmest water in July, August, September at around 19°C.
Can you swim in Vartry Reservoir in winter?
Yes, but winter temperatures drop to roughly 5°C. Below 12°C, cold-water shock is the main risk: enter slowly, never swim alone, and limit time in the water.
Is Vartry Reservoir safe for swimming?
Moving and inland water carries different risks from the sea: check flow after rain, avoid weirs and undercut banks, look for submerged rocks before jumping, and respect local access rules and water-quality notices.
Water safety tips
- Check the flow rate after heavy rain — inland water can rise and speed up within hours.
- Never jump before checking depth and submerged rocks; levels change through the season.
- Enter slowly to control cold-water shock, and get out before you start shivering.
- Swim with someone else and agree an exit point downstream before you start.
- Flooded quarries are deep and steeply shelved, with sharp thermoclines a metre or two down.
Swim season here: July, August, September.