Lagan has a very mildly warm and temperate climate with a good amount of rainfall occurring all through the year. Summers are very mild, while the winters are generally cold. The average annual temperature is around 7 degree Celsius.

• Winter: November to March is the coldest period of the year. The temperature is around -2 degree Celsius and snowfall is prevalent during these months. Rainfall is lesser than the annual average.
• Spring: The months of April and May see a slight increase in temperature to make the weather quite comfortable. The temperature range is around 7 – 8 degree Celsius.
• Summer: June to August show the highest rise in the mercury scale with temperatures ranging around 15 – 16 degree Celsius. Precipitation levels are highest during this period, making the weather mild and wet.
• Autumn: September and October have an average temperature of 9 degree Celsius. The rainfall level is also moderate during this period.

The best time to visit Lagan is from the months of April to September, when the weather is extremely comfortable and rainfall is also not much.