4. surface visibility ≥ 2500m and base of cloud ≥ 500ft The surface visibilty is at least 2500m and the height above ground level of the Base of the lowest Cloud Layer for 3/8 Cloud (or SCT) or more is at least 500ft. threshold Visibility 1600m Cloud 300ft 1 1 1 1 300 1 1 1 1 1600 threshold Visibility < 800m Or Cloud < 200ft 1 1 1 1 200 1 1 1 1 800 1. surface visibility < 800m or base of cloud < 200ft or sky obscured The surface visibilty is less than 800m or the height above ground level of the Base of the lowest Cloud Layer for 3/8 Cloud (or SCT) or more is below 200ft or the sky is obscured. threshold Visibility 3700m Cloud 700ft 1 1 1 1 700 1 1 1 1 3700 3. surface visibility ≥ 1600m and base of cloud ≥ 300ft The surface visibilty is at least 1600m and the height above ground level of the Base of the lowest Cloud Layer for 3/8 Cloud (or SCT) or more is at least 300ft. 6. surface visibility ≥ 5000m and base of cloud ≥ 1500ft The surface visibilty is at least 5000m and the height above ground level of the Base of the lowest Cloud Layer for 3/8 Cloud (or SCT) or more is at least 1500ft. 7. surface visibility ≥ 8000m and base of cloud ≥ 2500ft The surface visibilty is at least 8000m and the height above ground level of the Base of the lowest Cloud Layer for 3/8 Cloud (or SCT) or more is at least 2500ft. threshold Visibility 8000m Cloud 2500ft 1 1 1 1 2500 1 1 1 1 8000 threshold Visibility 5000m Cloud 1500ft 1 1 1 1 1500 1 1 1 1 5000 2. surface visibility ≥ 800m and base of cloud ≥ 200ft The surface visibilty is at least 800m and the height above ground level of the Base of the lowest Cloud Layer for 3/8 Cloud (or SCT) or more is at least 200ft. threshold Visibility 800m Cloud 200ft 1 1 1 1 200 1 1 1 1 800 5. surface visibility ≥ 3700m and base of cloud ≥ 700ft The surface visibilty is at least 3700m and the height above ground level of the Base of the lowest Cloud Layer for 3/8 Cloud (or SCT) or more is at least 700ft. threshold Visibility 2500m Cloud 500ft 1 1 1 1 500 1 1 1 1 2500