Fayetteville(AR)
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Fayetteville(AR) clear sky chart from 2005-11-06 to 2024-11-08.

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	11% 7% 2 6% 4 4 4 4 5% 7% 46%	100914
	Night	10% 6% 2 5% 4 3 4 3 5% 7% 50%	98273
Transparency	Day	36% 7% 11% 24% 18% 4	104565
	Night	33% 6% 11% 24% 20% 6%	102762
Seeing	Day	14% 11% 26% 27% 17% 5%	15463
	Night	14% 11% 30% 30% 14% 1	25271

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	13% 13% 3 5% 4 3 3 3 4 5% 44%	2847
	11th to 20th	Day	9% 7% 3 8% 3 3 3 3 4 6% 51%	2850
	21st to end	Day	20% 10% 2 5% 3 3 3 2 4 4 44%	3135
February	1st to 10th	Day	16% 10% 3 6% 6% 4 4 2 5% 4 40%	1710
	11th to 20th	Day	12% 10% 3 8% 3 4 4 3 4 6% 43%	1668
	21st to end	Day	15% 11% 3 6% 4 4 4 3 4 4 40%	1717
March	1st to 10th	Day	13% 8% 2 6% 4 4 4 4 4 6% 46%	3436
	11th to 20th	Day	12% 7% 2 5% 3 3 4 4 5% 7% 48%	3480
	21st to end	Day	16% 9% 3 8% 5% 5% 4 4 4 6% 36%	3814
April	1st to 10th	Day	11% 6% 2 7% 5% 4 4 4 6% 7% 44%	2194
	11th to 20th	Day	15% 8% 2 6% 4 4 5% 4 6% 6% 41%	2254
	21st to end	Day	15% 9% 3 7% 5% 4 4 4 5% 5% 39%	2280
May	1st to 10th	Day	16% 7% 3 7% 5% 5% 6% 5% 6% 6% 36%	4072
	11th to 20th	Day	10% 6% 3 8% 5% 4 5% 4 6% 7% 41%	4082
	21st to end	Day	12% 6% 2 7% 5% 5% 6% 4 7% 8% 38%	4477
June	1st to 10th	Day	8% 5% 2 6% 4 5% 6% 4 6% 10% 44%	2470
	11th to 20th	Day	5% 4 1 6% 5% 4 5% 5% 8% 10% 47%	2470
	21st to end	Day	3 4 1 4 5% 4 5% 4 7% 10% 54%	2470
July	1st to 10th	Day	9% 5% 2 6% 4 4 6% 4 7% 10% 42%	4120
	11th to 20th	Day	5% 5% 2 5% 4 3 5% 5% 6% 9% 51%	4120
	21st to end	Day	7% 5% 2 5% 5% 5% 6% 5% 8% 11% 41%	4465
August	1st to 10th	Day	5% 3 2 5% 3 4 4 3 5% 9% 57%	4104
	11th to 20th	Day	10% 5% 2 6% 4 4 4 4 6% 8% 47%	3982
	21st to end	Day	5% 4 2 5% 3 5% 6% 4 6% 8% 54%	4180
September	1st to 10th	Day	11% 5% 2 5% 3 4 3 3 5% 7% 53%	2280
	11th to 20th	Day	11% 6% 2 6% 4 4 4 4 6% 7% 47%	2123
	21st to end	Day	8% 5% 2 5% 3 4 4 4 5% 7% 54%	2062
October	1st to 10th	Day	9% 3 2 5% 3 3 4 3 5% 7% 55%	1900
	11th to 20th	Day	12% 5% 1 4 3 2 2 3 4 6% 58%	1900
	21st to end	Day	16% 6% 2 5% 4 3 3 2 4 5% 50%	2090
November	1st to 10th	Day	9% 7% 2 4 3 3 3 3 3 6% 57%	1928
	11th to 20th	Day	11% 7% 2 5% 3 4 3 3 5% 5% 52%	1862
	21st to end	Day	14% 8% 2 5% 5% 3 3 3 5% 7% 46%	1632
December	1st to 10th	Day	12% 8% 3 6% 4 3 5% 4 4 4 47%	1520
	11th to 20th	Day	11% 11% 3 7% 6% 4 4 3 4 5% 42%	2085
	21st to end	Day	11% 16% 8% 7% 5% 4 4 4 5% 6% 31%	3135
January	1st to 10th	Night	11% 8% 4 8% 5% 4 4 3 5% 5% 41%	4108
	11th to 20th	Night	10% 6% 2 7% 3 4 5% 3 5% 6% 49%	4120
	21st to end	Night	18% 11% 4 6% 3 2 2 2 3 5% 43%	4532
February	1st to 10th	Night	14% 11% 3 6% 4 4 4 3 5% 6% 42%	2470
	11th to 20th	Night	13% 9% 2 6% 4 3 4 3 4 6% 46%	2403
	21st to end	Night	12% 8% 2 6% 5% 3 5% 3 5% 6% 45%	1748
March	1st to 10th	Night	16% 7% 2 5% 3 3 4 3 4 6% 45%	3419
	11th to 20th	Night	12% 7% 2 6% 4 3 3 3 5% 6% 49%	3480
	21st to end	Night	11% 8% 3 7% 6% 4 4 4 5% 6% 42%	3817
April	1st to 10th	Night	11% 7% 2 4 4 3 3 3 6% 6% 50%	1985
	11th to 20th	Night	13% 7% 2 4 3 3 3 4 5% 7% 49%	1875
	21st to end	Night	15% 6% 2 6% 4 4 4 3 6% 6% 44%	1900
May	1st to 10th	Night	10% 8% 2 5% 4 3 4 4 5% 8% 46%	2828
	11th to 20th	Night	10% 7% 2 6% 4 5% 5% 4 7% 7% 43%	2823
	21st to end	Night	12% 6% 2 5% 4 5% 4 3 7% 9% 43%	3090
June	1st to 10th	Night	6% 3 2 4 3 3 3 4 5% 10% 55%	1710
	11th to 20th	Night	4 3 1 4 3 3 3 4 7% 10% 58%	1710
	21st to end	Night	2 2 1 2 3 3 4 4 7% 8% 64%	1710
July	1st to 10th	Night	10% 4 2 5% 3 4 4 4 5% 8% 51%	2850
	11th to 20th	Night	4 3 1 4 2 3 3 3 6% 8% 64%	2850
	21st to end	Night	6% 4 2 5% 3 4 4 4 7% 10% 52%	3098
August	1st to 10th	Night	3 2 1 4 4 3 4 4 6% 10% 59%	2836
	11th to 20th	Night	6% 4 1 5% 4 4 5% 4 6% 8% 54%	2854
	21st to end	Night	3 3 1 3 3 3 4 3 5% 9% 63%	3476
September	1st to 10th	Night	8% 4 1 3 3 4 4 3 5% 8% 57%	1900
	11th to 20th	Night	9% 4 2 5% 4 4 4 3 5% 7% 53%	2052
	21st to end	Night	8% 5% 2 4 3 3 3 4 4 7% 57%	2099
October	1st to 10th	Night	6% 3 1 3 3 3 3 3 5% 8% 62%	2280
	11th to 20th	Night	13% 3 1 3 3 2 3 3 5% 5% 59%	2280
	21st to end	Night	15% 6% 2 4 3 3 3 3 4 5% 53%	2508
November	1st to 10th	Night	11% 5% 2 4 3 3 4 2 4 5% 59%	2311
	11th to 20th	Night	10% 7% 2 3 3 3 3 3 5% 5% 56%	2317
	21st to end	Night	13% 7% 2 4 4 3 3 3 5% 6% 50%	2539
December	1st to 10th	Night	13% 9% 3 5% 3 3 4 3 4 6% 48%	2660
	11th to 20th	Night	12% 9% 3 8% 4 4 4 3 4 4 45%	3103
	21st to end	Night	12% 13% 8% 8% 4 4 4 3 4 5% 35%	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	41% 4 7% 23% 22% 2	2848
	11th to 20th	Day	35% 4 14% 23% 19% 4	2850
	21st to end	Day	45% 4 7% 21% 18% 6%	3135
February	1st to 10th	Day	48% 5% 9% 20% 15% 4	1710
	11th to 20th	Day	43% 5% 9% 22% 18% 4	1677
	21st to end	Day	46% 5% 8% 17% 16% 8%	1717
March	1st to 10th	Day	40% 6% 6% 19% 19% 11%	3436
	11th to 20th	Day	36% 7% 11% 23% 19% 4	3480
	21st to end	Day	48% 7% 9% 22% 12% 1	3814
April	1st to 10th	Day	38% 6% 12% 22% 18% 4	2194
	11th to 20th	Day	43% 7% 11% 19% 17% 4	2254
	21st to end	Day	47% 7% 9% 22% 14% 2	2280
May	1st to 10th	Day	46% 9% 9% 20% 14% 1	4110
	11th to 20th	Day	39% 11% 11% 24% 14%	4086
	21st to end	Day	41% 10% 14% 19% 14% 1	4489
June	1st to 10th	Day	35% 9% 16% 26% 14% 1	2470
	11th to 20th	Day	31% 9% 16% 28% 15% 2	2470
	21st to end	Day	25% 8% 16% 30% 18% 4	2470
July	1st to 10th	Day	34% 8% 18% 25% 13% 2	4056
	11th to 20th	Day	26% 7% 12% 35% 18% 1	4051
	21st to end	Day	34% 8% 19% 30% 9%	4325
August	1st to 10th	Day	24% 7% 15% 29% 21% 4	4090
	11th to 20th	Day	34% 7% 16% 28% 14% 1	4021
	21st to end	Day	27% 8% 14% 34% 14% 3	4179
September	1st to 10th	Day	32% 5% 11% 26% 17% 9%	2280
	11th to 20th	Day	34% 7% 11% 21% 23% 4	2123
	21st to end	Day	29% 5% 11% 24% 26% 5%	2062
October	1st to 10th	Day	17% 3 7% 16% 37% 20%	3160
	11th to 20th	Day	18% 3 4 19% 38% 17%	3140
	21st to end	Day	26% 4 9% 31% 24% 6%	3428
November	1st to 10th	Day	30% 5% 10% 25% 23% 8%	1928
	11th to 20th	Day	34% 5% 7% 23% 22% 10%	1862
	21st to end	Day	39% 5% 9% 19% 24% 4	1632
December	1st to 10th	Day	40% 5% 9% 24% 18% 4	1520
	11th to 20th	Day	44% 4 6% 18% 24% 3	2083
	21st to end	Day	52% 7% 8% 17% 13% 3	3135
January	1st to 10th	Night	43% 6% 7% 20% 21% 3	4108
	11th to 20th	Night	35% 6% 14% 22% 22% 2	4120
	21st to end	Night	46% 3 10% 18% 19% 4	4532
February	1st to 10th	Night	43% 4 10% 23% 15% 5%	2470
	11th to 20th	Night	39% 5% 8% 24% 18% 5%	2404
	21st to end	Night	41% 5% 8% 18% 21% 8%	1748
March	1st to 10th	Night	41% 6% 8% 18% 17% 10%	3419
	11th to 20th	Night	36% 6% 10% 26% 17% 4	3480
	21st to end	Night	42% 8% 11% 26% 13% 2	3817
April	1st to 10th	Night	34% 7% 10% 24% 20% 7%	1985
	11th to 20th	Night	35% 6% 9% 23% 21% 6%	1875
	21st to end	Night	40% 7% 10% 24% 17% 2	1900
May	1st to 10th	Night	37% 8% 13% 23% 16% 3	2855
	11th to 20th	Night	38% 9% 14% 25% 13% 1	2824
	21st to end	Night	36% 10% 17% 24% 13% 1	3099
June	1st to 10th	Night	22% 9% 16% 32% 18% 3	1710
	11th to 20th	Night	20% 8% 16% 33% 21% 2	1710
	21st to end	Night	17% 7% 17% 31% 23% 6%	1710
July	1st to 10th	Night	30% 8% 19% 24% 15% 4	2805
	11th to 20th	Night	18% 6% 12% 39% 24% 2	2796
	21st to end	Night	25% 7% 21% 31% 14% 1	2999
August	1st to 10th	Night	19% 7% 16% 34% 22% 2	2826
	11th to 20th	Night	28% 7% 20% 27% 16% 2	2881
	21st to end	Night	18% 6% 13% 39% 21% 3	3476
September	1st to 10th	Night	25% 6% 11% 29% 19% 9%	1900
	11th to 20th	Night	31% 6% 10% 23% 25% 5%	2052
	21st to end	Night	28% 5% 8% 24% 30% 6%	2099
October	1st to 10th	Night	13% 4 7% 14% 36% 26%	3800
	11th to 20th	Night	19% 4 5% 17% 34% 21%	3779
	21st to end	Night	27% 4 7% 30% 24% 8%	4120
November	1st to 10th	Night	30% 4 8% 24% 26% 9%	2311
	11th to 20th	Night	30% 4 8% 24% 26% 8%	2317
	21st to end	Night	37% 4 8% 21% 25% 6%	2539
December	1st to 10th	Night	39% 4 10% 22% 21% 4	2660
	11th to 20th	Night	42% 5% 7% 21% 19% 5%	3104
	21st to end	Night	52% 6% 8% 17% 14% 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	21% 19% 37% 18% 6%	270
	11th to 20th	Day	21% 25% 37% 13% 3	270
	21st to end	Day	18% 24% 39% 14% 5%	297
February	1st to 10th	Day	25% 20% 35% 17% 3	270
	11th to 20th	Day	22% 29% 35% 13% 1	270
	21st to end	Day	31% 29% 30% 10%	225
March	1st to 10th	Day	20% 22% 34% 20% 3	270
	11th to 20th	Day	24% 23% 34% 17% 2	270
	21st to end	Day	25% 25% 36% 10% 3	297
April	1st to 10th	Day	20% 25% 31% 17% 6% 2	374
	11th to 20th	Day	23% 19% 33% 20% 5%	452
	21st to end	Day	23% 18% 33% 18% 7%	460
May	1st to 10th	Day	17% 15% 37% 26% 6%	643
	11th to 20th	Day	15% 10% 32% 29% 12% 1	675
	21st to end	Day	11% 8% 35% 24% 17% 4	734
June	1st to 10th	Day	9% 4 20% 36% 23% 8%	680
	11th to 20th	Day	5% 4 22% 38% 26% 5%	680
	21st to end	Day	3 4 26% 35% 27% 5%	680
July	1st to 10th	Day	8% 2 17% 32% 30% 11%	671
	11th to 20th	Day	4 2 15% 36% 33% 10%	668
	21st to end	Day	8% 1 10% 34% 33% 13%	739
August	1st to 10th	Day	9% 2 14% 39% 30% 6%	676
	11th to 20th	Day	11% 3 11% 35% 32% 7%	632
	21st to end	Day	7% 2 10% 32% 35% 14%	539
September	1st to 10th	Day	11% 1 12% 34% 33% 10%	490
	11th to 20th	Day	7% 2 16% 41% 25% 10%	333
	21st to end	Day	9% 5% 23% 29% 25% 8%	300
October	1st to 10th	Day	11% 5% 29% 31% 20% 4	300
	11th to 20th	Day	13% 12% 38% 26% 9% 1	300
	21st to end	Day	25% 14% 32% 22% 5% 1	330
November	1st to 10th	Day	14% 15% 39% 22% 8% 2	291
	11th to 20th	Day	14% 21% 33% 23% 9% 1	270
	21st to end	Day	20% 20% 32% 21% 7%	270
December	1st to 10th	Day	17% 19% 37% 20% 6% 1	270
	11th to 20th	Day	21% 20% 37% 16% 6% 1	270
	21st to end	Day	19% 22% 42% 15% 2	297
January	1st to 10th	Night	17% 18% 35% 25% 5%	950
	11th to 20th	Night	17% 20% 39% 20% 3	950
	21st to end	Night	18% 16% 38% 25% 4	1045
February	1st to 10th	Night	19% 17% 38% 22% 3	950
	11th to 20th	Night	16% 20% 44% 17% 3	929
	21st to end	Night	20% 20% 37% 21% 2	492
March	1st to 10th	Night	19% 14% 35% 28% 4	570
	11th to 20th	Night	19% 14% 37% 26% 3	570
	21st to end	Night	18% 15% 41% 20% 6%	627
April	1st to 10th	Night	15% 18% 39% 24% 4	570
	11th to 20th	Night	17% 15% 37% 25% 7%	563
	21st to end	Night	17% 12% 42% 19% 8% 1	570
May	1st to 10th	Night	13% 9% 36% 34% 8%	570
	11th to 20th	Night	14% 6% 28% 35% 16% 1	561
	21st to end	Night	12% 6% 30% 32% 17% 3	617
June	1st to 10th	Night	6% 4 16% 43% 30% 1	570
	11th to 20th	Night	4 1 25% 44% 24% 2	570
	21st to end	Night	3 1 21% 46% 27% 3	570
July	1st to 10th	Night	6% 1 10% 42% 37% 4	555
	11th to 20th	Night	4 1 11% 43% 37% 4	552
	21st to end	Night	4 1 9% 41% 40% 4	624
August	1st to 10th	Night	3 2 11% 46% 35% 4	567
	11th to 20th	Night	7% 2 11% 47% 29% 4	564
	21st to end	Night	5% 1 11% 39% 40% 4	627
September	1st to 10th	Night	9% 2 11% 40% 35% 3	570
	11th to 20th	Night	12% 1 12% 42% 29% 5%	570
	21st to end	Night	10% 2 21% 37% 27% 3	579
October	1st to 10th	Night	8% 4 22% 38% 25% 3	760
	11th to 20th	Night	14% 8% 35% 32% 11%	760
	21st to end	Night	19% 10% 32% 28% 10% 1	836
November	1st to 10th	Night	12% 11% 36% 29% 11%	771
	11th to 20th	Night	14% 12% 36% 31% 7%	797
	21st to end	Night	20% 14% 35% 25% 8%	950
December	1st to 10th	Night	18% 14% 36% 26% 5%	950
	11th to 20th	Night	19% 14% 36% 26% 5%	950
	21st to end	Night	18% 18% 38% 22% 4	1045

Page generated at 2024-11-05 07:15:52. Version ac07

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