Cloud Cover, Humidity and Dew in Cricket
Also known as: does cloud cover help swing, overcast conditions in cricket, humidity and swing bowling, dew in cricket, dew factor, bowling in overcast conditions
Many players believe cloud cover makes the ball swing more, and captains often bowl first under grey skies. Science has not confirmed it. Lab studies find humidity has no measurable effect on swing, and cloud cover does not change the air flow directly. Dew is a different matter: it makes the ball wet and hard to grip.
Overcast days are part of cricket folklore. Teams often choose to bowl when it is cloudy and bat when the sun is out. A 2024 Cambridge review of 70 years of swing research found that studies have not shown any effect of humidity on swing. The authors also note that cloud cover does not directly change the air flow around the ball. They found that current theory does not fully explain the swing seen in pro matches either. So treat grey skies as a hint, not a rule.
What clearly matters is the ball. A shiny side, an upright seam and a skilled bowler produce swing in many conditions. The pitch matters too, since a green, damp surface helps seam movement.
Dew forms on the outfield in evening and night games in some climates. It soaks the ball, so bowlers and spinners struggle to grip it. Under Law 41.3.2.3 fielders may dry a wet ball on a cloth approved by the umpires. ICC playing conditions let umpires order ground staff to remove dew from the outfield. They also say that hours of play should be set to limit the effect of dew. Teams expecting heavy dew often prefer to bowl first.
Tips by skill level
Watch the first few overs before deciding how much the ball is doing. Let the ball, not the clouds, tell you.
In evening games with dew, plan for a wet ball late in the innings. Spinners may struggle to grip, so chances to score can rise.
Example
The forecast is grey and heavy. The home captain bowls first, hoping for swing. The batters still play late and leave well, because the ball may or may not move.
Why it matters
Conditions shape toss decisions and batting plans. Knowing what is proven and what is belief helps you prepare without being spooked by the sky.
Common mistakes
- Assuming the ball will swing just because it is cloudy
- Ignoring the pitch and the ball's condition when judging movement
- Forgetting that dew makes spin harder to grip in evening games
Frequently asked questions
Does cloud cover make the ball swing?
Many players think so, but research has not proven it. Studies find humidity has no measurable effect on swing, and cloud cover does not directly change the air flow. The ball's shine and seam matter more.
What is the dew factor in cricket?
Dew wets the outfield in some evening and night games. The ball gets wet and slippery, so bowlers, especially spinners, find it harder to grip. Fielders may dry it on an umpire-approved cloth.
Sources
- Grimshaw, Briggs & Atkins (2024), 'A review and reassessment of the aerodynamics of cricket ball swing', Flow 4, E6: section 5.2.1 (cloud cover not included as it does not directly affect air flow) and conclusion (ii) (no humidity effect shown)
- MCC Laws of Cricket, 2017 Code 4th Edition (2026), Law 41.3.2.3 (fielder may dry a wet ball on an approved cloth), p. 119
- ICC Men's ODI Playing Conditions (effective Oct 2026), clause 2.8.3 (umpires may order dew removal from the outfield), p. 7; clause 12.7.1 note (hours of play set to minimise dew), p. 19
Related terms
- Swing BowlingSwing bowling makes a fast-bowled ball curve sideways in the air, toward the batter (inswing) or away (outswing). The angled seam, helped by keeping one side shiny, makes the air flow differently over the two sides of the ball.
- Batting Against the New BallThe new ball is hard and shiny with a raised seam. It swings, seams and bounces most. Against it, know your off stump, leave well, play late with soft hands and score mostly from balls on your pads or short and wide. Once the shine and hardness fade, batting usually gets easier.
- Playing Swing and Seam BowlingTo play swing and seam bowling, know where your off stump is and leave balls you do not need to play. Watch the seam and shine in the bowler's hand, then play late under your eyes with a straight bat and soft hands. Let the ball come to you instead of reaching for it.
- Batting on Different PitchesRead the pitch before you bat and change your game to suit it. On a green, grassy pitch, leave more and play late. On a dry, turning pitch, use your feet and the sweep against spin. On a slow, low pitch, play straight and avoid cross-bat shots. On a bouncy pitch, judge length early and leave balls rising over the stumps.
- New BallThe new ball is a freshly manufactured cricket ball at the start of an innings (or available after a set number of overs). This swings and seams most readily due to its hard, lacquered surface and prominent seam.
Cricket analysis is in development
Motion Lab does not analyze this sport yet. Keep exploring the terms in this section.