Fayetteville
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Fayetteville clear sky chart from 2005-11-06 to 2024-11-03.

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	12% 6% 2 6% 5% 4 5% 4 6% 8% 42%	101087
	Night	14% 6% 2 6% 4 4 4 4 5% 7% 43%	97853
Transparency	Day	39% 7% 12% 20% 18% 4	100897
	Night	40% 7% 11% 19% 18% 6%	97713
Seeing	Day	15% 8% 23% 25% 20% 9%	15581
	Night	15% 7% 24% 34% 18% 2	25673

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	16% 5% 2 5% 4 3 3 2 3 6% 51%	2836
	11th to 20th	Day	13% 6% 2 5% 4 3 3 3 4 5% 54%	2840
	21st to end	Day	17% 8% 3 6% 4 3 3 3 4 5% 43%	3124
February	1st to 10th	Day	15% 6% 2 6% 4 3 4 4 6% 6% 44%	1710
	11th to 20th	Day	21% 6% 2 5% 3 3 3 3 4 5% 45%	1692
	21st to end	Day	18% 7% 2 6% 5% 4 3 3 5% 6% 41%	1727
March	1st to 10th	Day	22% 8% 3 6% 4 3 4 3 5% 6% 36%	3435
	11th to 20th	Day	9% 5% 2 5% 3 4 4 3 5% 7% 53%	3480
	21st to end	Day	18% 7% 2 6% 4 3 3 3 4 5% 44%	3815
April	1st to 10th	Day	10% 4 2 4 3 4 3 3 5% 8% 53%	2199
	11th to 20th	Day	10% 5% 1 4 5% 4 4 3 6% 7% 50%	2254
	21st to end	Day	12% 5% 1 5% 4 4 4 4 5% 6% 50%	2280
May	1st to 10th	Day	9% 7% 2 8% 6% 6% 5% 4 7% 10% 36%	3988
	11th to 20th	Day	15% 6% 3 7% 5% 5% 4 4 6% 8% 36%	4081
	21st to end	Day	6% 4 2 5% 4 5% 5% 4 6% 10% 49%	4476
June	1st to 10th	Day	9% 5% 3 6% 6% 5% 5% 6% 7% 8% 39%	2470
	11th to 20th	Day	8% 5% 2 5% 5% 5% 5% 5% 7% 10% 42%	2470
	21st to end	Day	7% 5% 2 7% 6% 5% 6% 5% 9% 11% 38%	2470
July	1st to 10th	Day	6% 5% 2 8% 6% 6% 7% 7% 9% 12% 32%	4120
	11th to 20th	Day	9% 7% 3 9% 6% 6% 7% 6% 9% 11% 28%	4120
	21st to end	Day	9% 9% 3 9% 7% 6% 6% 6% 8% 11% 27%	4466
August	1st to 10th	Day	20% 9% 4 9% 6% 5% 6% 5% 7% 8% 20%	4104
	11th to 20th	Day	10% 7% 3 7% 6% 6% 6% 5% 8% 10% 32%	3887
	21st to end	Day	6% 4 1 5% 5% 5% 5% 5% 7% 11% 47%	4180
September	1st to 10th	Day	9% 4 2 5% 5% 5% 6% 5% 8% 9% 43%	2280
	11th to 20th	Day	13% 6% 2 8% 4 4 5% 3 6% 8% 41%	2142
	21st to end	Day	17% 7% 2 7% 4 4 4 4 6% 6% 37%	2051
October	1st to 10th	Day	15% 6% 2 5% 4 3 3 3 5% 6% 47%	1900
	11th to 20th	Day	11% 5% 1 4 3 3 3 3 5% 6% 57%	1900
	21st to end	Day	11% 4 2 6% 3 3 3 2 4 6% 57%	2090
November	1st to 10th	Day	14% 5% 2 4 3 3 2 3 5% 6% 54%	1877
	11th to 20th	Day	14% 6% 1 4 3 2 4 3 4 6% 52%	1900
	21st to end	Day	13% 6% 2 5% 4 2 4 3 5% 7% 49%	1736
December	1st to 10th	Day	16% 7% 2 7% 4 3 4 5% 5% 7% 39%	1710
	11th to 20th	Day	15% 5% 2 5% 3 2 3 2 4 5% 54%	2153
	21st to end	Day	16% 7% 3 6% 4 3 4 4 4 6% 43%	3124
January	1st to 10th	Night	14% 6% 2 5% 4 3 3 3 6% 6% 47%	4109
	11th to 20th	Night	13% 7% 2 7% 4 5% 4 4 5% 6% 43%	4120
	21st to end	Night	16% 7% 3 6% 3 4 4 3 4 5% 44%	4532
February	1st to 10th	Night	17% 6% 2 5% 4 4 4 3 5% 6% 45%	2470
	11th to 20th	Night	19% 6% 2 6% 4 4 3 4 5% 5% 42%	2368
	21st to end	Night	14% 7% 2 5% 4 4 4 3 5% 6% 45%	1727
March	1st to 10th	Night	24% 10% 3 8% 4 3 4 3 4 5% 32%	3418
	11th to 20th	Night	13% 4 2 5% 4 4 5% 3 5% 6% 49%	3480
	21st to end	Night	17% 4 2 5% 4 3 4 3 5% 5% 47%	3817
April	1st to 10th	Night	11% 6% 2 5% 4 4 4 3 5% 7% 50%	1979
	11th to 20th	Night	11% 4 2 5% 4 4 4 3 5% 7% 50%	1875
	21st to end	Night	11% 4 1 5% 3 4 5% 5% 5% 7% 49%	1900
May	1st to 10th	Night	9% 7% 3 8% 4 5% 5% 3 6% 9% 40%	2921
	11th to 20th	Night	14% 9% 3 8% 5% 4 5% 3 5% 7% 37%	2812
	21st to end	Night	7% 5% 2 6% 5% 5% 6% 5% 6% 9% 45%	3079
June	1st to 10th	Night	10% 6% 2 5% 5% 6% 6% 6% 8% 10% 36%	1710
	11th to 20th	Night	10% 6% 2 6% 5% 5% 5% 4 6% 11% 39%	1710
	21st to end	Night	7% 5% 2 7% 5% 5% 6% 5% 9% 11% 37%	1710
July	1st to 10th	Night	9% 8% 3 8% 5% 5% 7% 6% 8% 11% 30%	2840
	11th to 20th	Night	12% 8% 3 7% 5% 5% 6% 5% 9% 12% 29%	2840
	21st to end	Night	15% 11% 4 9% 6% 5% 6% 4 6% 8% 25%	3087
August	1st to 10th	Night	20% 9% 3 9% 6% 5% 6% 4 6% 9% 24%	2825
	11th to 20th	Night	8% 6% 2 9% 6% 5% 7% 5% 8% 11% 32%	2908
	21st to end	Night	6% 4 2 5% 5% 5% 5% 5% 7% 10% 46%	3476
September	1st to 10th	Night	9% 5% 2 6% 4 4 4 4 7% 9% 44%	1900
	11th to 20th	Night	13% 6% 3 7% 5% 5% 4 4 6% 8% 39%	2033
	21st to end	Night	18% 7% 2 8% 5% 4 4 3 4 6% 38%	2128
October	1st to 10th	Night	14% 6% 2 5% 3 3 3 3 5% 6% 49%	2280
	11th to 20th	Night	11% 5% 2 5% 4 3 4 2 4 5% 55%	2280
	21st to end	Night	10% 5% 2 4 3 3 3 2 4 7% 56%	2508
November	1st to 10th	Night	13% 6% 2 5% 3 3 3 3 4 4 54%	2246
	11th to 20th	Night	14% 7% 2 5% 4 3 3 3 4 6% 49%	2280
	21st to end	Night	13% 4 2 5% 4 3 4 2 5% 6% 51%	2441
December	1st to 10th	Night	17% 7% 2 6% 4 3 4 3 5% 6% 42%	2470
	11th to 20th	Night	17% 7% 2 5% 4 3 3 3 4 4 49%	3042
	21st to end	Night	16% 6% 2 5% 4 3 4 3 4 6% 46%	4532

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	36% 4 6% 23% 24% 6%	2837
	11th to 20th	Day	35% 4 5% 19% 30% 8%	2840
	21st to end	Day	43% 5% 5% 16% 21% 10%	3124
February	1st to 10th	Day	40% 4 11% 19% 19% 5%	1710
	11th to 20th	Day	41% 4 7% 17% 23% 7%	1701
	21st to end	Day	44% 5% 9% 16% 20% 6%	1727
March	1st to 10th	Day	49% 5% 7% 16% 14% 8%	3435
	11th to 20th	Day	30% 6% 9% 16% 27% 12%	3480
	21st to end	Day	43% 4 7% 21% 20% 4	3815
April	1st to 10th	Day	29% 4 12% 22% 25% 8%	2199
	11th to 20th	Day	32% 5% 11% 22% 21% 8%	2254
	21st to end	Day	33% 8% 12% 24% 19% 5%	2280
May	1st to 10th	Day	41% 10% 17% 19% 12% 2	4024
	11th to 20th	Day	45% 7% 11% 21% 15% 1	4085
	21st to end	Day	28% 8% 17% 22% 21% 3	4489
June	1st to 10th	Day	39% 10% 15% 21% 14% 1	2470
	11th to 20th	Day	34% 9% 17% 23% 15% 2	2470
	21st to end	Day	36% 11% 18% 20% 13% 2	2470
July	1st to 10th	Day	38% 12% 18% 20% 10% 2	4055
	11th to 20th	Day	45% 13% 23% 13% 4 1	4051
	21st to end	Day	47% 12% 16% 16% 9% 1	4324
August	1st to 10th	Day	58% 10% 17% 10% 5%	4091
	11th to 20th	Day	43% 10% 15% 21% 10% 1	3926
	21st to end	Day	30% 7% 15% 30% 15% 2	4180
September	1st to 10th	Day	35% 11% 15% 17% 18% 4	2280
	11th to 20th	Day	40% 7% 12% 16% 21% 4	2142
	21st to end	Day	45% 6% 9% 18% 16% 4	2051
October	1st to 10th	Day	38% 5% 9% 21% 23% 4	1900
	11th to 20th	Day	29% 5% 9% 24% 23% 9%	1900
	21st to end	Day	30% 4 7% 22% 27% 10%	2090
November	1st to 10th	Day	33% 4 8% 20% 27% 9%	1877
	11th to 20th	Day	34% 4 8% 21% 25% 9%	1900
	21st to end	Day	35% 4 8% 23% 22% 8%	1736
December	1st to 10th	Day	43% 6% 11% 19% 17% 4	1710
	11th to 20th	Day	35% 3 7% 22% 25% 9%	2150
	21st to end	Day	41% 5% 7% 21% 23% 2	3124
January	1st to 10th	Night	36% 4 8% 20% 27% 5%	4109
	11th to 20th	Night	41% 5% 8% 15% 24% 7%	4120
	21st to end	Night	42% 5% 6% 15% 24% 8%	4532
February	1st to 10th	Night	40% 4 9% 19% 21% 7%	2470
	11th to 20th	Night	44% 4 9% 15% 21% 7%	2370
	21st to end	Night	40% 5% 9% 18% 21% 8%	1727
March	1st to 10th	Night	54% 6% 7% 13% 15% 5%	3418
	11th to 20th	Night	34% 7% 8% 12% 24% 17%	3480
	21st to end	Night	38% 5% 9% 21% 21% 6%	3817
April	1st to 10th	Night	35% 6% 10% 18% 23% 9%	1979
	11th to 20th	Night	33% 6% 10% 22% 21% 9%	1875
	21st to end	Night	32% 7% 12% 24% 20% 5%	1900
May	1st to 10th	Night	38% 9% 16% 22% 12% 2	2950
	11th to 20th	Night	45% 7% 11% 21% 15% 1	2813
	21st to end	Night	31% 10% 16% 24% 16% 3	3087
June	1st to 10th	Night	38% 11% 18% 21% 12% 1	1710
	11th to 20th	Night	38% 9% 19% 21% 13% 1	1710
	21st to end	Night	37% 11% 18% 22% 11% 2	1710
July	1st to 10th	Night	44% 13% 16% 18% 7% 1	2795
	11th to 20th	Night	45% 12% 24% 13% 4 1	2786
	21st to end	Night	55% 9% 13% 15% 9%	2988
August	1st to 10th	Night	56% 9% 18% 14% 4	2814
	11th to 20th	Night	43% 11% 20% 20% 6% 1	2935
	21st to end	Night	31% 8% 13% 31% 16% 2	3476
September	1st to 10th	Night	35% 9% 16% 20% 15% 5%	1900
	11th to 20th	Night	42% 7% 13% 17% 18% 3	2033
	21st to end	Night	48% 6% 12% 16% 15% 4	2128
October	1st to 10th	Night	36% 6% 9% 21% 23% 6%	2280
	11th to 20th	Night	31% 5% 9% 22% 23% 11%	2280
	21st to end	Night	29% 4 8% 21% 26% 12%	2508
November	1st to 10th	Night	35% 4 6% 17% 27% 12%	2246
	11th to 20th	Night	36% 4 8% 16% 24% 12%	2280
	21st to end	Night	34% 5% 7% 21% 26% 9%	2441
December	1st to 10th	Night	42% 6% 11% 17% 18% 6%	2470
	11th to 20th	Night	39% 4 7% 19% 22% 9%	3044
	21st to end	Night	40% 4 7% 22% 25% 3	4532

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	15% 20% 37% 23% 4	270
	11th to 20th	Day	17% 23% 34% 18% 6% 1	270
	21st to end	Day	18% 20% 39% 17% 6%	297
February	1st to 10th	Day	18% 17% 37% 21% 6%	270
	11th to 20th	Day	31% 14% 38% 15% 2	295
	21st to end	Day	23% 16% 34% 20% 7%	382
March	1st to 10th	Day	20% 16% 30% 26% 9%	460
	11th to 20th	Day	20% 14% 37% 21% 6% 1	460
	21st to end	Day	21% 12% 34% 22% 9% 1	506
April	1st to 10th	Day	18% 18% 30% 23% 10% 2	460
	11th to 20th	Day	11% 16% 29% 24% 17% 4	452
	21st to end	Day	15% 10% 27% 25% 19% 3	460
May	1st to 10th	Day	10% 14% 33% 22% 14% 6%	463
	11th to 20th	Day	14% 5% 19% 28% 24% 10%	487
	21st to end	Day	13% 5% 16% 25% 24% 16%	529
June	1st to 10th	Day	12% 3 18% 31% 26% 10%	490
	11th to 20th	Day	12% 2 15% 27% 29% 16%	490
	21st to end	Day	6% 3 16% 27% 32% 16%	490
July	1st to 10th	Day	10% 2 6% 25% 35% 23%	485
	11th to 20th	Day	9% 1 8% 24% 37% 21%	484
	21st to end	Day	6% 2 10% 29% 39% 13%	532
August	1st to 10th	Day	14% 4 11% 24% 28% 19%	486
	11th to 20th	Day	11% 3 10% 22% 33% 22%	479
	21st to end	Day	12% 2 8% 26% 29% 24%	539
September	1st to 10th	Day	10% 3 13% 25% 25% 24%	490
	11th to 20th	Day	16% 4 12% 25% 30% 13%	490
	21st to end	Day	20% 4 20% 26% 23% 7%	490
October	1st to 10th	Day	19% 6% 20% 22% 24% 10%	490
	11th to 20th	Day	12% 7% 26% 27% 22% 6%	490
	21st to end	Day	12% 7% 23% 31% 22% 6%	539
November	1st to 10th	Day	19% 7% 23% 30% 16% 5%	463
	11th to 20th	Day	17% 8% 33% 30% 11% 2	460
	21st to end	Day	14% 11% 27% 30% 16% 2	296
December	1st to 10th	Day	20% 11% 40% 20% 7%	270
	11th to 20th	Day	19% 11% 36% 21% 11% 2	270
	21st to end	Day	22% 13% 34% 19% 10% 3	297
January	1st to 10th	Night	19% 11% 33% 29% 7% 1	760
	11th to 20th	Night	17% 12% 33% 31% 7%	760
	21st to end	Night	19% 10% 37% 31% 4	836
February	1st to 10th	Night	19% 9% 35% 32% 4	760
	11th to 20th	Night	22% 14% 38% 24% 1	743
	21st to end	Night	19% 12% 36% 29% 4	628
March	1st to 10th	Night	18% 11% 34% 30% 6% 1	760
	11th to 20th	Night	17% 12% 37% 27% 7% 1	760
	21st to end	Night	18% 11% 34% 31% 6%	836
April	1st to 10th	Night	16% 13% 34% 31% 7%	760
	11th to 20th	Night	13% 11% 32% 32% 12%	751
	21st to end	Night	13% 6% 31% 40% 9%	760
May	1st to 10th	Night	10% 10% 31% 36% 13%	641
	11th to 20th	Night	14% 5% 22% 41% 18% 1	561
	21st to end	Night	10% 2 16% 38% 32% 2	617
June	1st to 10th	Night	11% 2 17% 44% 22% 3	570
	11th to 20th	Night	11% 3 12% 39% 29% 6%	570
	21st to end	Night	8% 3 15% 38% 33% 4	570
July	1st to 10th	Night	10% 2 9% 36% 38% 5%	555
	11th to 20th	Night	9% 1 7% 37% 41% 5%	552
	21st to end	Night	8% 3 10% 40% 36% 3	624
August	1st to 10th	Night	12% 2 9% 34% 38% 4	567
	11th to 20th	Night	11% 2 9% 36% 37% 5%	635
	21st to end	Night	12% 2 9% 33% 38% 7%	836
September	1st to 10th	Night	11% 2 10% 33% 38% 6%	760
	11th to 20th	Night	16% 2 12% 31% 35% 5%	760
	21st to end	Night	22% 5% 16% 31% 24% 3	760
October	1st to 10th	Night	17% 4 16% 29% 29% 5%	760
	11th to 20th	Night	13% 4 26% 32% 22% 2	760
	21st to end	Night	13% 6% 24% 33% 21% 3	836
November	1st to 10th	Night	16% 6% 22% 36% 17% 3	749
	11th to 20th	Night	17% 8% 27% 33% 14% 1	760
	21st to end	Night	15% 7% 28% 33% 17% 1	760
December	1st to 10th	Night	19% 9% 27% 36% 8%	760
	11th to 20th	Night	19% 8% 27% 36% 10%	760
	21st to end	Night	21% 10% 26% 35% 9%	836

Page generated at 2024-10-31 03:39:24. Version ac07

Copyright © 2024 Attilla Danko.