How reliable is Shannon Airport?
Month-by-month weather risk and connection guidance for Shannon Airport. We don’t yet have on-time performance history here — see why below.
Weather favorability
year-round climate
On-time performance data isn’t available for SNN yet
Our historical on-time and cancellation record currently covers the US, UK, Brazil, and Australia, so we don’t score departure reliability at Shannon Airport yet. Weather climatology below comes from global airport observations and still applies.
Advertisement
Weather by month
When the weather works for you at Shannon
A calm-weather score (0–100) for each month from decades of airport observations — how often conditions disrupt flying, not temperature. Higher is calmer.
Calmest month
Calmest flying weather of the year · 98/100 favorability
Roughest month
Most disruptive — low visibility & fog, freezing conditions · 92/100 favorability
The read on SNN
What the numbers say about flying through Shannon Airport
PlaneSane doesn't yet have on-time and cancellation history for Shannon Airport, so it isn't scored for departure reliability here — that record currently covers the US, UK, Brazil, and Australia. The weather and connection context below comes from separate global sources and still applies.
On weather, Shannon is an unusually calm-weather airport year-round. April is the calmest stretch for flying, scoring 98 out of 100 for favorable conditions, while January is the most disruptive at 92, driven mainly by low visibility & fog and freezing conditions. The year is relatively steady, so no single month stands out as one to avoid on weather alone.
None of this guarantees your specific flight — it’s the backdrop. To turn it into a booking, score real flights to Shannon, read how we weigh it all in how the PlaneSane Score works, and brush up with how to pick a reliable flight and avoiding weather delays.
Common questions about SNN
- What is the best month to fly from SNN for good weather?
- April has the calmest flying weather at Shannon Airport. January is the most disruptive, mainly from low visibility & fog and freezing conditions.
Planning a trip through Shannon?
Score real flights to and from SNN on reliability, weather, and connection safety — not just price.