Wingham
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Wingham clear sky chart from 2005-11-06 to 2025-02-25.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.

Observation Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(no limit)	Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

By Month

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

		Occurrence of each Forecast	Data Points
Cloud Cover	Day	14% 12% 5% 10% 6% 5% 4 4 5% 6% 29%	108657
	Night	14% 14% 5% 12% 6% 5% 4 3 5% 5% 26%	110035
Transparency	Day	55% 5% 11% 18% 10% 1	112266
	Night	58% 5% 10% 17% 9% 1	114590
Seeing	Day	20% 12% 28% 23% 12% 5%	15416
	Night	21% 11% 29% 27% 11% 1	24838

By Month

Percentage Cloud Cover NE (2006-)
Color Meanings: Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	11% 19% 11% 22% 10% 5% 4 3 3 5% 8%	3321
	11th to 20th	Day	8% 21% 10% 28% 14% 8% 3 1 2 1 4	3822
	21st to end	Day	14% 19% 9% 23% 9% 6% 5% 3 3 3 7%	4466
February	1st to 10th	Day	13% 20% 7% 18% 10% 5% 4 3 3 4 13%	1800
	11th to 20th	Day	12% 15% 10% 18% 12% 5% 4 3 4 3 13%	1753
	21st to end	Day	15% 20% 7% 12% 8% 4 4 3 4 4 19%	1594
March	1st to 10th	Day	15% 16% 6% 12% 6% 4 3 2 3 5% 26%	3331
	11th to 20th	Day	10% 18% 8% 12% 5% 4 3 4 5% 6% 26%	3480
	21st to end	Day	15% 14% 5% 11% 6% 5% 4 4 5% 5% 27%	3815
April	1st to 10th	Day	17% 16% 6% 8% 4 4 4 4 5% 5% 28%	2171
	11th to 20th	Day	18% 13% 2 6% 4 4 4 3 5% 6% 34%	2442
	21st to end	Day	20% 11% 4 7% 4 4 3 3 5% 7% 33%	2470
May	1st to 10th	Day	16% 10% 3 7% 5% 4 4 3 6% 7% 35%	4108
	11th to 20th	Day	17% 9% 2 7% 4 4 4 3 6% 8% 35%	4166
	21st to end	Day	14% 6% 2 5% 4 4 4 3 4 8% 46%	4837
June	1st to 10th	Day	14% 7% 2 7% 5% 5% 5% 4 6% 7% 38%	2742
	11th to 20th	Day	11% 6% 2 6% 4 4 5% 4 6% 8% 42%	2850
	21st to end	Day	16% 6% 2 5% 4 4 4 4 5% 7% 41%	2850
July	1st to 10th	Day	11% 5% 3 7% 5% 5% 5% 5% 7% 8% 39%	4760
	11th to 20th	Day	12% 5% 2 5% 4 4 5% 5% 6% 8% 45%	4459
	21st to end	Day	9% 5% 2 5% 4 5% 5% 4 7% 10% 44%	4466
August	1st to 10th	Day	12% 7% 2 7% 5% 6% 5% 5% 7% 8% 37%	4104
	11th to 20th	Day	13% 7% 2 7% 5% 5% 6% 6% 7% 9% 33%	4044
	21st to end	Day	10% 6% 2 6% 4 4 5% 4 7% 9% 42%	4500
September	1st to 10th	Day	12% 7% 3 7% 5% 5% 4 4 6% 9% 39%	2234
	11th to 20th	Day	12% 6% 3 6% 4 4 4 3 6% 8% 44%	2090
	21st to end	Day	17% 8% 3 7% 5% 5% 4 3 7% 8% 34%	2090
October	1st to 10th	Day	19% 8% 3 8% 5% 5% 4 3 5% 6% 34%	1938
	11th to 20th	Day	21% 15% 3 9% 5% 5% 5% 3 5% 6% 22%	1900
	21st to end	Day	26% 17% 4 8% 5% 5% 4 3 5% 5% 17%	2028
November	1st to 10th	Day	15% 18% 4 9% 5% 5% 4 3 4 7% 25%	1762
	11th to 20th	Day	15% 21% 4 11% 6% 5% 5% 4 6% 6% 18%	1602
	21st to end	Day	17% 25% 9% 11% 6% 5% 4 3 5% 5% 12%	1600
December	1st to 10th	Day	15% 30% 13% 15% 6% 4 4 3 3 3 5%	2600
	11th to 20th	Day	20% 23% 8% 17% 7% 4 3 2 4 4 8%	2986
	21st to end	Day	23% 23% 9% 12% 5% 5% 3 3 4 4 9%	3476
January	1st to 10th	Night	12% 18% 9% 23% 10% 6% 4 4 3 4 7%	6642
	11th to 20th	Night	10% 16% 10% 24% 16% 8% 4 2 3 2 5%	6068
	21st to end	Night	13% 17% 9% 20% 7% 7% 6% 3 4 4 9%	6490
February	1st to 10th	Night	14% 20% 6% 16% 11% 6% 5% 3 4 4 13%	2600
	11th to 20th	Night	12% 15% 8% 17% 9% 7% 5% 4 5% 6% 14%	2533
	21st to end	Night	14% 15% 6% 15% 8% 5% 4 4 5% 5% 20%	1954
March	1st to 10th	Night	12% 14% 5% 9% 5% 4 4 3 5% 6% 33%	3508
	11th to 20th	Night	9% 15% 6% 10% 5% 4 4 3 5% 6% 32%	3479
	21st to end	Night	14% 11% 5% 11% 5% 5% 4 3 4 5% 32%	3817
April	1st to 10th	Night	19% 15% 3 7% 4 4 4 3 5% 5% 30%	2014
	11th to 20th	Night	17% 11% 3 5% 4 4 4 3 5% 7% 35%	1698
	21st to end	Night	16% 12% 3 8% 5% 4 4 4 5% 6% 31%	1710
May	1st to 10th	Night	15% 8% 2 7% 4 4 4 3 5% 7% 41%	2833
	11th to 20th	Night	15% 8% 3 7% 5% 5% 3 4 5% 6% 39%	2725
	21st to end	Night	11% 5% 1 6% 4 4 4 3 5% 7% 49%	2738
June	1st to 10th	Night	13% 7% 2 6% 6% 3 5% 4 6% 7% 41%	1433
	11th to 20th	Night	11% 6% 2 7% 5% 5% 4 5% 6% 9% 40%	1330
	21st to end	Night	13% 6% 1 7% 4 4 4 4 5% 8% 44%	1330
July	1st to 10th	Night	7% 5% 3 7% 4 5% 4 3 5% 8% 49%	2210
	11th to 20th	Night	11% 5% 1 4 3 4 3 3 5% 7% 53%	2485
	21st to end	Night	6% 7% 2 6% 4 5% 5% 4 6% 7% 48%	3087
August	1st to 10th	Night	11% 7% 2 7% 5% 5% 4 3 6% 6% 44%	2825
	11th to 20th	Night	14% 8% 3 6% 4 4 4 4 6% 8% 41%	2785
	21st to end	Night	11% 5% 2 7% 4 4 4 3 5% 7% 48%	3124
September	1st to 10th	Night	10% 5% 2 6% 5% 4 4 4 6% 8% 45%	1942
	11th to 20th	Night	11% 6% 2 4 3 4 4 4 5% 7% 51%	2090
	21st to end	Night	15% 7% 3 8% 4 4 4 3 5% 6% 38%	2090
October	1st to 10th	Night	18% 9% 3 7% 4 4 4 3 5% 6% 37%	2242
	11th to 20th	Night	21% 13% 4 8% 5% 4 5% 3 5% 7% 26%	2280
	21st to end	Night	24% 14% 4 9% 6% 5% 4 4 5% 4 22%	2570
November	1st to 10th	Night	16% 13% 4 9% 6% 5% 4 3 5% 6% 29%	2536
	11th to 20th	Night	16% 19% 6% 10% 5% 5% 5% 4 5% 5% 19%	2795
	21st to end	Night	20% 21% 7% 11% 5% 4 5% 3 4 5% 15%	2800
December	1st to 10th	Night	12% 24% 8% 18% 7% 6% 6% 4 4 4 7%	4580
	11th to 20th	Night	12% 25% 9% 17% 6% 5% 4 3 4 4 12%	5208
	21st to end	Night	21% 21% 9% 13% 6% 4 4 3 4 4 10%	7484

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	79% 4 6% 8% 3	3322
	11th to 20th	Day	90% 2 3 2 2	3856
	21st to end	Day	83% 5% 6% 4 2	4466
February	1st to 10th	Day	77% 4 6% 11% 2	1800
	11th to 20th	Day	74% 6% 6% 10% 3 1	1762
	21st to end	Day	69% 5% 8% 12% 6%	1594
March	1st to 10th	Day	62% 4 11% 16% 7% 1	3334
	11th to 20th	Day	59% 5% 11% 17% 6% 1	3480
	21st to end	Day	58% 5% 10% 14% 10% 1	3815
April	1st to 10th	Day	58% 5% 10% 17% 10%	2171
	11th to 20th	Day	50% 5% 11% 20% 13% 1	2442
	21st to end	Day	52% 4 12% 18% 12% 2	2470
May	1st to 10th	Day	47% 5% 12% 19% 15% 1	4120
	11th to 20th	Day	46% 7% 14% 24% 8% 1	4170
	21st to end	Day	37% 6% 11% 22% 19% 5%	4837
June	1st to 10th	Day	43% 7% 12% 23% 14% 2	2742
	11th to 20th	Day	38% 7% 12% 26% 17% 1	2850
	21st to end	Day	43% 6% 12% 25% 14% 1	2850
July	1st to 10th	Day	42% 4 15% 21% 17% 2	4686
	11th to 20th	Day	36% 5% 11% 34% 13% 1	4380
	21st to end	Day	35% 5% 13% 25% 19% 2	4324
August	1st to 10th	Day	43% 7% 13% 23% 14% 1	4091
	11th to 20th	Day	45% 6% 16% 24% 10%	4083
	21st to end	Day	38% 4 14% 30% 13% 1	4500
September	1st to 10th	Day	42% 7% 14% 24% 12% 2	2234
	11th to 20th	Day	37% 6% 13% 29% 14%	2090
	21st to end	Day	47% 6% 13% 24% 9% 1	2090
October	1st to 10th	Day	46% 5% 10% 24% 14% 1	3224
	11th to 20th	Day	50% 3 12% 23% 11% 1	3140
	21st to end	Day	60% 4 15% 17% 5%	3317
November	1st to 10th	Day	59% 6% 10% 17% 8%	1762
	11th to 20th	Day	64% 7% 11% 11% 6% 1	1602
	21st to end	Day	75% 6% 8% 9% 2	1600
December	1st to 10th	Day	85% 3 6% 4 1	2600
	11th to 20th	Day	81% 4 7% 7% 1	2986
	21st to end	Day	79% 4 7% 7% 3	3476
January	1st to 10th	Night	80% 4 6% 9% 2	6642
	11th to 20th	Night	87% 3 4 4 2	6109
	21st to end	Night	79% 4 8% 6% 3	6490
February	1st to 10th	Night	75% 5% 7% 11% 2	2600
	11th to 20th	Night	70% 6% 9% 11% 4	2535
	21st to end	Night	64% 6% 10% 13% 7%	1954
March	1st to 10th	Night	52% 6% 14% 20% 7%	3518
	11th to 20th	Night	52% 6% 14% 19% 9% 1	3480
	21st to end	Night	50% 6% 11% 21% 11% 1	3817
April	1st to 10th	Night	56% 5% 8% 18% 13% 1	2014
	11th to 20th	Night	50% 4 9% 19% 17% 1	1698
	21st to end	Night	51% 6% 9% 16% 16% 2	1710
May	1st to 10th	Night	42% 7% 11% 20% 16% 4	2840
	11th to 20th	Night	45% 7% 11% 22% 13% 2	2726
	21st to end	Night	33% 7% 12% 24% 21% 3	2739
June	1st to 10th	Night	40% 6% 10% 25% 16% 2	1433
	11th to 20th	Night	39% 5% 12% 24% 17% 3	1330
	21st to end	Night	37% 6% 12% 26% 18% 1	1330
July	1st to 10th	Night	34% 3 13% 25% 19% 6%	2175
	11th to 20th	Night	32% 4 11% 34% 18% 1	2441
	21st to end	Night	35% 5% 15% 26% 18% 1	2988
August	1st to 10th	Night	40% 4 11% 27% 16% 1	2814
	11th to 20th	Night	42% 5% 14% 25% 13% 1	2812
	21st to end	Night	37% 4 10% 34% 14% 1	3124
September	1st to 10th	Night	37% 6% 12% 28% 15% 2	1942
	11th to 20th	Night	32% 6% 12% 30% 19% 1	2090
	21st to end	Night	45% 6% 13% 24% 12%	2090
October	1st to 10th	Night	38% 5% 8% 28% 21% 1	3736
	11th to 20th	Night	49% 3 15% 19% 13%	3779
	21st to end	Night	53% 4 15% 21% 8%	4231
November	1st to 10th	Night	56% 6% 10% 20% 7%	2536
	11th to 20th	Night	65% 6% 10% 13% 5% 1	2795
	21st to end	Night	72% 5% 11% 10% 2	2800
December	1st to 10th	Night	81% 3 10% 4 1	4580
	11th to 20th	Night	77% 4 8% 8% 3	5208
	21st to end	Night	78% 4 6% 8% 3	7484

Seeing (when cloud cover <= 80%)
Color Meanings: Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	22% 20% 35% 17% 4 1	237
	11th to 20th	Day	21% 21% 42% 11% 4 1	300
	21st to end	Day	24% 20% 34% 19% 2 1	330
February	1st to 10th	Day	25% 22% 40% 11% 3	300
	11th to 20th	Day	25% 22% 42% 10% 2	300
	21st to end	Day	31% 26% 29% 13% 1	237
March	1st to 10th	Day	24% 17% 38% 14% 7% 1	393
	11th to 20th	Day	23% 14% 35% 21% 7% 1	460
	21st to end	Day	28% 12% 33% 21% 6% 1	506
April	1st to 10th	Day	22% 18% 32% 19% 8% 1	460
	11th to 20th	Day	28% 17% 26% 15% 9% 4	452
	21st to end	Day	25% 12% 32% 22% 8% 2	460
May	1st to 10th	Day	20% 12% 29% 25% 10% 3	463
	11th to 20th	Day	21% 9% 25% 25% 16% 5%	487
	21st to end	Day	17% 6% 24% 29% 17% 7%	529
June	1st to 10th	Day	14% 12% 27% 30% 14% 4	572
	11th to 20th	Day	14% 10% 29% 29% 15% 3	680
	21st to end	Day	18% 7% 31% 31% 11% 3	680
July	1st to 10th	Day	11% 6% 23% 31% 22% 8%	671
	11th to 20th	Day	14% 6% 27% 30% 16% 7%	616
	21st to end	Day	10% 4 27% 35% 18% 7%	532
August	1st to 10th	Day	12% 5% 23% 28% 20% 12%	486
	11th to 20th	Day	16% 4 18% 29% 18% 16%	479
	21st to end	Day	16% 6% 19% 29% 20% 9%	539
September	1st to 10th	Day	13% 9% 23% 28% 18% 10%	490
	11th to 20th	Day	11% 5% 18% 28% 24% 15%	490
	21st to end	Day	16% 9% 28% 25% 14% 8%	490
October	1st to 10th	Day	21% 9% 27% 23% 15% 5%	490
	11th to 20th	Day	27% 15% 29% 22% 6% 2	490
	21st to end	Day	32% 17% 29% 17% 4 1	477
November	1st to 10th	Day	27% 19% 30% 15% 8%	300
	11th to 20th	Day	30% 19% 32% 15% 3 3	200
	21st to end	Day	29% 18% 38% 14% 3	200
December	1st to 10th	Day	31% 25% 27% 14% 4	200
	11th to 20th	Day	30% 25% 30% 14% 2 1	200
	21st to end	Day	32% 19% 37% 10% 2	220
January	1st to 10th	Night	23% 17% 35% 18% 6% 1	1000
	11th to 20th	Night	26% 17% 34% 19% 4	892
	21st to end	Night	21% 12% 36% 24% 6%	880
February	1st to 10th	Night	23% 16% 36% 22% 3	800
	11th to 20th	Night	22% 16% 35% 21% 5%	783
	21st to end	Night	21% 18% 38% 19% 4	647
March	1st to 10th	Night	19% 16% 36% 21% 8%	760
	11th to 20th	Night	20% 14% 37% 23% 6% 1	760
	21st to end	Night	23% 12% 29% 27% 9%	836
April	1st to 10th	Night	27% 12% 31% 25% 5%	760
	11th to 20th	Night	24% 10% 30% 24% 10% 1	574
	21st to end	Night	23% 9% 27% 31% 9%	570
May	1st to 10th	Night	19% 6% 31% 29% 13% 1	570
	11th to 20th	Night	19% 7% 25% 35% 13% 1	513
	21st to end	Night	12% 3 28% 40% 17%	411
June	1st to 10th	Night	16% 4 27% 39% 13% 1	380
	11th to 20th	Night	13% 4 26% 41% 16%	380
	21st to end	Night	14% 5% 24% 41% 15% 1	380
July	1st to 10th	Night	5% 3 17% 53% 20% 1	370
	11th to 20th	Night	11% 3 20% 40% 23% 3	480
	21st to end	Night	10% 2 18% 45% 24% 1	624
August	1st to 10th	Night	12% 2 16% 39% 30% 2	567
	11th to 20th	Night	11% 2 17% 35% 30% 5%	564
	21st to end	Night	14% 3 19% 36% 25% 3	627
September	1st to 10th	Night	11% 5% 24% 34% 19% 5%	759
	11th to 20th	Night	13% 3 18% 36% 25% 4	760
	21st to end	Night	16% 8% 23% 32% 17% 4	760
October	1st to 10th	Night	21% 8% 26% 29% 15% 1	760
	11th to 20th	Night	26% 11% 25% 29% 8% 1	760
	21st to end	Night	31% 12% 31% 23% 3	836
November	1st to 10th	Night	25% 12% 27% 26% 9% 1	780
	11th to 20th	Night	25% 16% 32% 19% 6% 1	800
	21st to end	Night	29% 14% 31% 22% 4	800
December	1st to 10th	Night	31% 15% 32% 18% 5%	800
	11th to 20th	Night	24% 18% 37% 17% 3 1	800
	21st to end	Night	31% 13% 34% 19% 3	1095

Page generated at 2025-02-22 06:51:34. Version ac07

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