Waynesville
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Waynesville clear sky chart from 2005-11-06 to 2025-09-19.

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	9% 7% 3 8% 6% 6% 6% 5% 6% 8% 37%	126145
	Night	8% 8% 3 8% 5% 5% 6% 4 6% 8% 40%	122920
Transparency	Day	39% 9% 13% 17% 15% 6%	129869
	Night	36% 10% 15% 18% 16% 6%	127265
Seeing	Day	17% 16% 25% 21% 14% 7%	16152
	Night	14% 12% 23% 28% 18% 4	26166

By Month

Percentage Cloud Cover SE (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	7% 7% 3 7% 4 4 4 4 6% 7% 47%	4056
	11th to 20th	Day	5% 5% 3 8% 5% 4 4 4 4 4 54%	4060
	21st to end	Day	9% 10% 4 8% 5% 4 4 3 4 5% 43%	4466
February	1st to 10th	Day	8% 8% 3 8% 5% 5% 6% 4 5% 7% 41%	1924
	11th to 20th	Day	8% 9% 3 9% 7% 5% 4 4 5% 6% 39%	1948
	21st to end	Day	9% 9% 3 8% 7% 5% 4 5% 6% 6% 39%	1650
March	1st to 10th	Day	13% 7% 2 6% 5% 5% 5% 4 5% 6% 40%	4772
	11th to 20th	Day	6% 6% 2 7% 5% 4 4 3 5% 6% 52%	4980
	21st to end	Day	11% 8% 3 8% 5% 5% 5% 3 5% 6% 42%	5465
April	1st to 10th	Day	7% 8% 3 6% 5% 5% 5% 5% 7% 8% 40%	2200
	11th to 20th	Day	10% 7% 3 7% 6% 4 6% 4 5% 6% 41%	2406
	21st to end	Day	11% 7% 3 7% 5% 5% 5% 4 5% 7% 42%	2600
May	1st to 10th	Day	8% 8% 4 11% 6% 6% 6% 5% 6% 8% 31%	5862
	11th to 20th	Day	12% 8% 4 9% 7% 7% 7% 5% 8% 8% 25%	5861
	21st to end	Day	8% 6% 3 8% 6% 6% 6% 5% 7% 9% 34%	6433
June	1st to 10th	Day	9% 8% 3 7% 8% 8% 7% 5% 8% 10% 26%	2600
	11th to 20th	Day	7% 7% 3 9% 7% 7% 7% 7% 8% 10% 28%	2600
	21st to end	Day	8% 7% 2 8% 7% 7% 7% 6% 7% 10% 31%	2600
July	1st to 10th	Day	6% 5% 3 8% 7% 7% 7% 6% 8% 10% 32%	5900
	11th to 20th	Day	7% 6% 3 10% 8% 8% 9% 7% 9% 10% 22%	5900
	21st to end	Day	9% 7% 3 11% 10% 10% 10% 7% 9% 8% 16%	6424
August	1st to 10th	Day	12% 8% 3 9% 7% 7% 7% 6% 8% 9% 25%	4234
	11th to 20th	Day	8% 6% 3 9% 8% 7% 8% 6% 8% 11% 27%	4174
	21st to end	Day	7% 6% 3 9% 6% 6% 7% 5% 7% 8% 36%	4289
September	1st to 10th	Day	11% 7% 3 9% 7% 6% 7% 5% 6% 7% 31%	2200
	11th to 20th	Day	16% 9% 3 9% 5% 5% 6% 4 6% 7% 30%	2178
	21st to end	Day	14% 7% 3 7% 6% 4 5% 4 6% 7% 36%	2090
October	1st to 10th	Day	11% 6% 2 7% 6% 4 4 4 5% 6% 46%	2081
	11th to 20th	Day	7% 6% 3 6% 4 5% 4 3 5% 6% 52%	1900
	21st to end	Day	9% 6% 2 5% 4 3 4 2 4 7% 53%	2090
November	1st to 10th	Day	7% 6% 2 5% 4 5% 3 4 5% 6% 53%	1833
	11th to 20th	Day	7% 7% 2 6% 4 3 4 4 5% 8% 50%	1800
	21st to end	Day	8% 8% 2 6% 4 4 4 4 5% 7% 47%	1800
December	1st to 10th	Day	6% 6% 2 5% 5% 4 8% 3 6% 5% 49%	2930
	11th to 20th	Day	7% 8% 2 7% 6% 6% 7% 5% 7% 6% 38%	3373
	21st to end	Day	8% 6% 2 7% 5% 6% 7% 5% 5% 7% 43%	4466
January	1st to 10th	Night	7% 7% 3 8% 5% 4 5% 4 4 7% 46%	5889
	11th to 20th	Night	4 6% 3 9% 5% 5% 5% 4 5% 5% 49%	5900
	21st to end	Night	8% 12% 3 6% 5% 4 4 3 5% 5% 45%	6490
February	1st to 10th	Night	6% 8% 3 7% 5% 6% 5% 4 6% 8% 41%	2475
	11th to 20th	Night	9% 11% 3 9% 6% 4 5% 4 6% 7% 38%	2338
	21st to end	Night	9% 8% 4 8% 5% 6% 6% 4 7% 7% 37%	1980
March	1st to 10th	Night	12% 11% 3 8% 5% 5% 6% 4 5% 6% 35%	5079
	11th to 20th	Night	6% 7% 2 6% 5% 4 4 3 6% 7% 49%	4980
	21st to end	Night	9% 7% 2 6% 5% 5% 7% 4 5% 7% 41%	5467
April	1st to 10th	Night	8% 8% 3 7% 5% 5% 5% 4 6% 8% 42%	2200
	11th to 20th	Night	7% 8% 3 6% 5% 4 4 4 5% 7% 46%	1958
	21st to end	Night	8% 8% 3 6% 4 4 5% 4 5% 7% 46%	1800
May	1st to 10th	Night	7% 7% 3 10% 6% 6% 7% 5% 7% 8% 32%	4033
	11th to 20th	Night	12% 10% 4 11% 6% 6% 7% 4 6% 9% 26%	4032
	21st to end	Night	7% 7% 3 9% 5% 6% 6% 5% 6% 9% 36%	4421
June	1st to 10th	Night	6% 6% 3 8% 6% 6% 6% 6% 9% 11% 34%	1800
	11th to 20th	Night	4 5% 2 7% 5% 5% 5% 6% 9% 13% 39%	1800
	21st to end	Night	6% 4 2 5% 5% 6% 5% 6% 9% 11% 40%	1800
July	1st to 10th	Night	6% 5% 2 6% 6% 7% 7% 6% 9% 11% 35%	4058
	11th to 20th	Night	6% 4 2 7% 7% 8% 8% 6% 8% 10% 34%	4057
	21st to end	Night	7% 7% 3 10% 8% 7% 7% 6% 8% 10% 27%	4427
August	1st to 10th	Night	8% 6% 3 9% 5% 6% 7% 5% 8% 11% 31%	2915
	11th to 20th	Night	9% 8% 2 8% 6% 6% 7% 5% 8% 9% 33%	2875
	21st to end	Night	7% 5% 2 6% 4 4 6% 5% 7% 9% 46%	3570
September	1st to 10th	Night	8% 8% 3 8% 6% 5% 7% 5% 7% 8% 36%	2200
	11th to 20th	Night	12% 9% 3 9% 5% 5% 4 5% 5% 8% 35%	2179
	21st to end	Night	11% 7% 3 7% 4 4 5% 3 5% 8% 43%	2090
October	1st to 10th	Night	11% 8% 2 5% 4 4 4 3 5% 7% 48%	2097
	11th to 20th	Night	8% 7% 3 7% 5% 4 5% 3 5% 5% 49%	2280
	21st to end	Night	8% 8% 2 6% 3 4 4 3 4 6% 52%	2508
November	1st to 10th	Night	8% 7% 3 6% 4 4 5% 4 6% 6% 47%	2460
	11th to 20th	Night	8% 9% 2 7% 4 4 4 4 5% 7% 47%	2600
	21st to end	Night	8% 7% 2 5% 5% 4 6% 4 6% 6% 47%	2600
December	1st to 10th	Night	6% 7% 3 8% 4 4 7% 4 6% 5% 46%	4250
	11th to 20th	Night	9% 8% 3 9% 5% 6% 7% 4 4 6% 39%	4822
	21st to end	Night	8% 6% 3 10% 6% 6% 6% 5% 6% 8% 36%	6490

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	30% 7% 7% 17% 33% 6%	4057
	11th to 20th	Day	29% 7% 8% 13% 32% 12%	4060
	21st to end	Day	35% 10% 8% 12% 24% 10%	4466
February	1st to 10th	Day	42% 6% 9% 20% 17% 6%	1924
	11th to 20th	Day	44% 7% 8% 15% 19% 7%	1958
	21st to end	Day	43% 8% 9% 13% 20% 8%	1650
March	1st to 10th	Day	38% 6% 9% 14% 18% 15%	4772
	11th to 20th	Day	31% 6% 7% 14% 22% 21%	4980
	21st to end	Day	40% 6% 10% 24% 14% 6%	5465
April	1st to 10th	Day	37% 7% 13% 20% 18% 4	2200
	11th to 20th	Day	41% 8% 9% 18% 20% 5%	2406
	21st to end	Day	40% 8% 11% 24% 15% 2	2600
May	1st to 10th	Day	45% 10% 14% 19% 11% 1	5897
	11th to 20th	Day	48% 11% 16% 16% 8%	5865
	21st to end	Day	39% 13% 15% 17% 14% 3	6447
June	1st to 10th	Day	49% 13% 16% 16% 6% 1	2600
	11th to 20th	Day	44% 15% 17% 14% 10% 1	2600
	21st to end	Day	44% 11% 16% 16% 9% 2	2600
July	1st to 10th	Day	40% 15% 19% 18% 9%	5835
	11th to 20th	Day	47% 15% 25% 10% 3	5831
	21st to end	Day	54% 16% 17% 8% 5%	6240
August	1st to 10th	Day	49% 11% 17% 19% 4	4221
	11th to 20th	Day	43% 12% 22% 12% 8% 2	4213
	21st to end	Day	39% 11% 15% 24% 10% 1	4289
September	1st to 10th	Day	46% 10% 12% 16% 13% 3	2200
	11th to 20th	Day	51% 8% 9% 17% 13% 1	2178
	21st to end	Day	44% 8% 13% 17% 14% 5%	2090
October	1st to 10th	Day	28% 7% 9% 15% 28% 12%	3458
	11th to 20th	Day	23% 4 5% 19% 22% 26%	3140
	21st to end	Day	22% 4 10% 24% 23% 17%	3428
November	1st to 10th	Day	30% 5% 10% 18% 26% 10%	1833
	11th to 20th	Day	31% 6% 7% 20% 26% 10%	1800
	21st to end	Day	35% 6% 7% 21% 23% 7%	1800
December	1st to 10th	Day	30% 7% 12% 16% 27% 9%	2930
	11th to 20th	Day	37% 6% 14% 15% 18% 8%	3370
	21st to end	Day	32% 7% 16% 26% 15% 3	4466
January	1st to 10th	Night	31% 9% 10% 17% 24% 9%	5889
	11th to 20th	Night	30% 8% 9% 11% 30% 11%	5900
	21st to end	Night	38% 6% 8% 14% 22% 12%	6490
February	1st to 10th	Night	39% 7% 13% 18% 19% 5%	2475
	11th to 20th	Night	45% 7% 9% 18% 17% 5%	2339
	21st to end	Night	44% 7% 10% 16% 16% 6%	1980
March	1st to 10th	Night	40% 10% 9% 14% 20% 6%	5079
	11th to 20th	Night	30% 6% 9% 20% 19% 16%	4980
	21st to end	Night	37% 8% 14% 23% 12% 5%	5467
April	1st to 10th	Night	36% 8% 15% 21% 18% 3	2200
	11th to 20th	Night	35% 8% 11% 22% 20% 4	1958
	21st to end	Night	37% 9% 14% 26% 14% 1	1800
May	1st to 10th	Night	41% 13% 17% 23% 6% 1	4060
	11th to 20th	Night	45% 14% 20% 16% 5%	4033
	21st to end	Night	35% 14% 20% 21% 8% 1	4429
June	1st to 10th	Night	38% 14% 21% 19% 7% 1	1800
	11th to 20th	Night	31% 15% 26% 22% 6% 1	1800
	21st to end	Night	33% 13% 21% 20% 11% 2	1800
July	1st to 10th	Night	34% 17% 23% 21% 5%	4015
	11th to 20th	Night	34% 19% 32% 12% 2 1	4006
	21st to end	Night	44% 17% 23% 11% 5%	4297
August	1st to 10th	Night	40% 13% 28% 16% 4	2904
	11th to 20th	Night	39% 14% 29% 13% 6%	2902
	21st to end	Night	30% 11% 21% 29% 9% 1	3570
September	1st to 10th	Night	40% 13% 15% 18% 11% 2	2200
	11th to 20th	Night	45% 10% 13% 18% 13% 1	2179
	21st to end	Night	38% 8% 13% 22% 16% 3	2090
October	1st to 10th	Night	27% 7% 13% 19% 26% 8%	3500
	11th to 20th	Night	26% 5% 7% 19% 21% 22%	3779
	21st to end	Night	23% 4 10% 26% 20% 17%	4120
November	1st to 10th	Night	33% 8% 11% 19% 20% 9%	2460
	11th to 20th	Night	35% 5% 8% 18% 23% 10%	2600
	21st to end	Night	35% 7% 8% 21% 22% 7%	2600
December	1st to 10th	Night	33% 7% 12% 16% 25% 6%	4250
	11th to 20th	Night	39% 8% 11% 16% 18% 8%	4824
	21st to end	Night	38% 8% 15% 18% 17% 3	6490

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	26% 31% 32% 9% 1	300
	11th to 20th	Day	32% 29% 25% 12% 3	300
	21st to end	Day	26% 36% 28% 8% 2	330
February	1st to 10th	Day	25% 31% 33% 8% 2	300
	11th to 20th	Day	40% 30% 24% 5%	300
	21st to end	Day	36% 36% 21% 6% 1	249
March	1st to 10th	Day	27% 24% 30% 12% 7%	423
	11th to 20th	Day	25% 28% 29% 14% 4 1	500
	21st to end	Day	23% 26% 33% 13% 5%	550
April	1st to 10th	Day	22% 24% 27% 19% 6% 1	500
	11th to 20th	Day	20% 25% 25% 18% 9% 2	492
	21st to end	Day	17% 18% 30% 22% 10% 3	500
May	1st to 10th	Day	17% 23% 30% 18% 8% 5%	503
	11th to 20th	Day	17% 13% 28% 23% 11% 7%	527
	21st to end	Day	14% 13% 23% 28% 14% 9%	573
June	1st to 10th	Day	11% 9% 28% 25% 16% 10%	530
	11th to 20th	Day	6% 8% 27% 23% 24% 11%	530
	21st to end	Day	8% 8% 27% 26% 18% 13%	530
July	1st to 10th	Day	8% 4 21% 26% 26% 16%	525
	11th to 20th	Day	7% 4 15% 28% 26% 19%	524
	21st to end	Day	10% 4 14% 28% 27% 17%	576
August	1st to 10th	Day	15% 6% 20% 23% 20% 16%	526
	11th to 20th	Day	10% 4 18% 29% 24% 14%	519
	21st to end	Day	9% 5% 17% 26% 26% 16%	583
September	1st to 10th	Day	9% 5% 21% 28% 26% 12%	530
	11th to 20th	Day	15% 6% 19% 25% 24% 10%	522
	21st to end	Day	18% 9% 19% 28% 20% 5%	490
October	1st to 10th	Day	17% 10% 21% 27% 19% 8%	490
	11th to 20th	Day	11% 17% 26% 27% 16% 3	490
	21st to end	Day	16% 15% 24% 29% 12% 4	539
November	1st to 10th	Day	14% 16% 32% 25% 10% 3	371
	11th to 20th	Day	21% 21% 34% 18% 5%	300
	21st to end	Day	17% 26% 32% 19% 5% 1	300
December	1st to 10th	Day	27% 29% 28% 12% 4	300
	11th to 20th	Day	19% 25% 34% 18% 4	300
	21st to end	Day	22% 22% 40% 12% 4 1	330
January	1st to 10th	Night	20% 19% 34% 21% 5% 1	800
	11th to 20th	Night	19% 23% 34% 20% 5%	800
	21st to end	Night	16% 21% 38% 22% 3	880
February	1st to 10th	Night	15% 21% 32% 28% 4	800
	11th to 20th	Night	23% 21% 36% 19% 2	783
	21st to end	Night	24% 24% 31% 19% 3	660
March	1st to 10th	Night	20% 19% 32% 25% 4	800
	11th to 20th	Night	19% 21% 29% 23% 8% 1	800
	21st to end	Night	18% 19% 34% 21% 7%	880
April	1st to 10th	Night	17% 23% 28% 23% 8% 1	800
	11th to 20th	Night	15% 16% 31% 24% 12% 2	649
	21st to end	Night	13% 14% 25% 36% 13% 1	600
May	1st to 10th	Night	14% 11% 29% 29% 16% 2	600
	11th to 20th	Night	12% 9% 23% 32% 22% 3	591
	21st to end	Night	10% 5% 17% 29% 31% 7%	650
June	1st to 10th	Night	6% 4 19% 37% 28% 6%	600
	11th to 20th	Night	4 4 17% 31% 34% 11%	600
	21st to end	Night	6% 3 13% 33% 39% 7%	600
July	1st to 10th	Night	8% 2 9% 30% 43% 8%	585
	11th to 20th	Night	8% 1 8% 28% 42% 13%	582
	21st to end	Night	7% 2 7% 26% 46% 12%	657
August	1st to 10th	Night	7% 4 9% 30% 40% 10%	597
	11th to 20th	Night	9% 3 9% 31% 39% 9%	594
	21st to end	Night	10% 2 9% 28% 39% 11%	689
September	1st to 10th	Night	10% 4 13% 28% 38% 8%	800
	11th to 20th	Night	16% 5% 13% 28% 32% 7%	793
	21st to end	Night	15% 6% 15% 33% 27% 4	760
October	1st to 10th	Night	14% 9% 18% 25% 26% 8%	760
	11th to 20th	Night	14% 10% 24% 32% 18% 2	760
	21st to end	Night	14% 12% 18% 38% 14% 3	836
November	1st to 10th	Night	12% 10% 22% 34% 18% 4	780
	11th to 20th	Night	16% 13% 24% 32% 12% 3	800
	21st to end	Night	16% 15% 26% 30% 14% 1	800
December	1st to 10th	Night	18% 16% 31% 29% 7%	800
	11th to 20th	Night	14% 18% 30% 30% 8% 1	800
	21st to end	Night	19% 16% 30% 30% 5%	880

Page generated at 2025-09-16 01:49:15. Version ac07

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