Tupelo
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Tupelo clear sky chart from 2005-11-06 to 2026-01-17.

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% 4 4 5% 4 6% 7% 43%	126877
	Night	13% 6% 2 6% 4 4 4 3 5% 7% 46%	124876
Transparency	Day	39% 6% 10% 22% 18% 5%	130591
	Night	37% 5% 10% 21% 20% 7%	129226
Seeing	Day	14% 8% 20% 24% 22% 12%	16706
	Night	15% 6% 23% 31% 21% 4	26487

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	17% 10% 2 9% 3 3 2 2 3 5% 44%	3726
	11th to 20th	Day	16% 6% 2 6% 3 3 3 2 4 5% 50%	4134
	21st to end	Day	19% 10% 2 5% 3 3 4 3 4 5% 42%	4793
February	1st to 10th	Day	20% 8% 3 5% 5% 3 4 3 4 6% 39%	2000
	11th to 20th	Day	20% 8% 3 6% 4 4 4 3 4 4 39%	1948
	21st to end	Day	20% 9% 2 6% 3 3 3 3 5% 5% 41%	1650
March	1st to 10th	Day	19% 9% 3 8% 5% 5% 4 3 5% 4 34%	4480
	11th to 20th	Day	12% 6% 3 5% 5% 4 4 4 5% 7% 46%	4750
	21st to end	Day	13% 6% 3 7% 5% 5% 4 4 5% 7% 41%	5960
April	1st to 10th	Day	12% 6% 3 5% 4 4 4 5% 6% 7% 44%	2400
	11th to 20th	Day	15% 7% 2 5% 3 3 4 3 5% 5% 47%	2374
	21st to end	Day	11% 5% 2 7% 5% 4 4 4 5% 8% 45%	2400
May	1st to 10th	Day	15% 7% 2 7% 5% 5% 5% 4 7% 8% 34%	5446
	11th to 20th	Day	14% 8% 3 8% 6% 5% 6% 4 7% 9% 32%	5861
	21st to end	Day	14% 7% 3 7% 5% 5% 5% 4 6% 7% 38%	6433
June	1st to 10th	Day	8% 6% 2 7% 5% 5% 4 4 7% 10% 42%	2712
	11th to 20th	Day	5% 4 2 6% 5% 5% 6% 5% 8% 9% 46%	2800
	21st to end	Day	5% 4 2 6% 6% 5% 5% 4 6% 9% 48%	2800
July	1st to 10th	Day	5% 5% 2 8% 6% 7% 7% 6% 8% 10% 37%	6360
	11th to 20th	Day	7% 4 2 6% 4 6% 8% 6% 11% 14% 32%	6296
	21st to end	Day	9% 6% 3 7% 6% 6% 6% 6% 9% 12% 30%	6043
August	1st to 10th	Day	3 2 1 5% 3 4 5% 4 6% 8% 59%	3905
	11th to 20th	Day	6% 4 2 7% 4 5% 5% 4 7% 10% 47%	3849
	21st to end	Day	6% 4 2 5% 4 4 4 4 7% 8% 52%	4312
September	1st to 10th	Day	8% 5% 2 6% 5% 5% 5% 4 7% 7% 46%	2400
	11th to 20th	Day	12% 6% 2 7% 4 5% 4 3 5% 7% 46%	2267
	21st to end	Day	11% 4 1 5% 4 4 4 3 5% 7% 53%	2200
October	1st to 10th	Day	9% 4 2 5% 3 3 3 3 5% 6% 58%	2200
	11th to 20th	Day	8% 5% 1 5% 4 3 3 3 5% 5% 58%	2014
	21st to end	Day	15% 5% 2 5% 3 4 3 2 3 5% 53%	2179
November	1st to 10th	Day	11% 5% 2 5% 3 3 3 3 5% 6% 56%	1852
	11th to 20th	Day	12% 5% 1 4 4 4 3 3 4 6% 55%	1890
	21st to end	Day	15% 7% 2 6% 4 4 3 3 4 6% 46%	1890
December	1st to 10th	Day	15% 9% 3 6% 4 4 4 3 5% 4 44%	3020
	11th to 20th	Day	20% 9% 3 6% 4 4 3 3 3 4 43%	3463
	21st to end	Day	16% 8% 3 7% 4 4 4 3 5% 6% 41%	4070
January	1st to 10th	Night	18% 8% 2 7% 4 4 4 3 4 4 42%	6443
	11th to 20th	Night	17% 7% 2 6% 4 3 3 3 3 4 49%	5979
	21st to end	Night	21% 8% 2 5% 3 2 3 2 3 5% 45%	6153
February	1st to 10th	Night	18% 9% 3 7% 3 3 3 3 4 5% 42%	2400
	11th to 20th	Night	21% 7% 3 6% 4 3 3 3 4 4 42%	2338
	21st to end	Night	21% 6% 2 7% 4 4 3 3 4 6% 40%	1980
March	1st to 10th	Night	19% 9% 3 7% 4 4 4 3 5% 6% 37%	5373
	11th to 20th	Night	11% 6% 2 5% 4 3 4 3 5% 6% 51%	5238
	21st to end	Night	17% 7% 3 7% 4 3 4 3 3 5% 44%	4967
April	1st to 10th	Night	12% 6% 2 6% 4 3 4 3 5% 8% 47%	2000
	11th to 20th	Night	12% 5% 2 5% 4 3 4 3 5% 7% 50%	1975
	21st to end	Night	10% 7% 2 6% 4 4 4 4 5% 6% 48%	2000
May	1st to 10th	Night	16% 8% 3 7% 4 4 4 3 6% 8% 38%	4444
	11th to 20th	Night	17% 10% 3 9% 5% 5% 4 3 4 6% 35%	4032
	21st to end	Night	10% 6% 2 7% 5% 5% 5% 5% 6% 9% 40%	4421
June	1st to 10th	Night	7% 5% 2 7% 5% 5% 4 3 5% 10% 47%	1681
	11th to 20th	Night	4 4 1 4 4 4 5% 4 7% 11% 53%	1600
	21st to end	Night	5% 4 1 5% 4 4 4 4 6% 11% 53%	1600
July	1st to 10th	Night	4 5% 2 6% 5% 5% 6% 5% 8% 12% 42%	3618
	11th to 20th	Night	6% 5% 2 6% 4 4 4 5% 8% 13% 44%	3663
	21st to end	Night	7% 7% 3 8% 5% 5% 6% 5% 9% 13% 31%	4798
August	1st to 10th	Night	2 2 1 3 3 3 3 3 6% 9% 65%	3244
	11th to 20th	Night	3 3 2 5% 4 4 5% 4 7% 10% 54%	3200
	21st to end	Night	5% 4 2 5% 4 4 4 5% 6% 10% 53%	3586
September	1st to 10th	Night	8% 5% 2 5% 4 5% 5% 4 6% 7% 49%	2000
	11th to 20th	Night	12% 5% 1 6% 4 4 4 3 5% 7% 49%	2111
	21st to end	Night	8% 5% 2 5% 3 3 3 3 6% 8% 54%	2200
October	1st to 10th	Night	7% 2 1 4 3 3 3 2 4 7% 63%	2200
	11th to 20th	Night	10% 5% 2 4 3 3 3 2 4 5% 58%	2382
	21st to end	Night	16% 5% 2 5% 3 3 3 2 3 5% 54%	2660
November	1st to 10th	Night	11% 5% 2 5% 3 3 3 3 5% 6% 55%	2666
	11th to 20th	Night	10% 5% 2 4 3 3 3 3 5% 6% 54%	2730
	21st to end	Night	16% 6% 2 5% 3 3 3 3 4 5% 49%	2730
December	1st to 10th	Night	19% 6% 2 5% 3 2 2 3 4 5% 47%	4380
	11th to 20th	Night	19% 8% 2 6% 3 3 3 3 3 4 45%	4952
	21st to end	Night	19% 7% 2 6% 4 4 4 4 5% 6% 40%	7132

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	45% 2 6% 26% 18% 2	3727
	11th to 20th	Day	38% 3 5% 25% 26% 3	4134
	21st to end	Day	47% 3 5% 19% 21% 5%	4793
February	1st to 10th	Day	47% 4 7% 20% 17% 5%	2000
	11th to 20th	Day	49% 3 5% 19% 18% 6%	1958
	21st to end	Day	47% 4 7% 15% 21% 7%	1650
March	1st to 10th	Day	52% 4 6% 13% 16% 9%	4480
	11th to 20th	Day	38% 5% 6% 19% 21% 11%	4750
	21st to end	Day	43% 4 9% 22% 20% 2	5962
April	1st to 10th	Day	39% 6% 9% 22% 19% 6%	2400
	11th to 20th	Day	38% 5% 7% 21% 21% 7%	2374
	21st to end	Day	37% 6% 9% 25% 21% 2	2400
May	1st to 10th	Day	46% 8% 10% 25% 10% 2	5481
	11th to 20th	Day	47% 8% 15% 21% 9% 1	5865
	21st to end	Day	45% 7% 10% 24% 14% 2	6447
June	1st to 10th	Day	37% 8% 12% 22% 19% 3	2712
	11th to 20th	Day	32% 8% 13% 24% 20% 2	2800
	21st to end	Day	33% 7% 15% 23% 18% 4	2800
July	1st to 10th	Day	38% 10% 16% 24% 11% 1	6291
	11th to 20th	Day	36% 11% 22% 27% 4 1	6221
	21st to end	Day	43% 10% 22% 21% 5%	5871
August	1st to 10th	Day	21% 7% 12% 36% 22% 2	3893
	11th to 20th	Day	32% 8% 15% 27% 15% 2	3885
	21st to end	Day	29% 7% 12% 23% 25% 4	4311
September	1st to 10th	Day	35% 8% 12% 23% 18% 6%	2400
	11th to 20th	Day	38% 6% 12% 16% 23% 5%	2267
	21st to end	Day	30% 5% 12% 23% 21% 9%	2200
October	1st to 10th	Day	19% 3 5% 15% 32% 26%	3590
	11th to 20th	Day	18% 2 5% 21% 36% 19%	3254
	21st to end	Day	27% 2 5% 24% 32% 10%	3493
November	1st to 10th	Day	30% 4 9% 20% 29% 9%	1852
	11th to 20th	Day	33% 3 7% 21% 28% 9%	1890
	21st to end	Day	40% 3 7% 20% 24% 5%	1890
December	1st to 10th	Day	45% 3 4 23% 22% 3	3020
	11th to 20th	Day	48% 2 5% 22% 17% 6%	3460
	21st to end	Day	44% 3 10% 24% 17% 2	4070
January	1st to 10th	Night	46% 3 6% 21% 22% 2	6443
	11th to 20th	Night	41% 3 4 20% 27% 5%	5979
	21st to end	Night	44% 2 6% 19% 22% 7%	6153
February	1st to 10th	Night	46% 3 7% 19% 20% 5%	2400
	11th to 20th	Night	47% 3 6% 18% 19% 6%	2339
	21st to end	Night	47% 4 5% 16% 19% 9%	1980
March	1st to 10th	Night	50% 3 7% 14% 18% 8%	5373
	11th to 20th	Night	34% 4 6% 19% 20% 17%	5238
	21st to end	Night	45% 3 6% 20% 20% 5%	4967
April	1st to 10th	Night	36% 4 10% 23% 20% 7%	2000
	11th to 20th	Night	34% 3 7% 22% 25% 9%	1975
	21st to end	Night	35% 6% 10% 24% 21% 4	2000
May	1st to 10th	Night	45% 6% 12% 22% 14% 2	4474
	11th to 20th	Night	50% 6% 13% 21% 9% 1	4033
	21st to end	Night	40% 8% 11% 22% 16% 2	4429
June	1st to 10th	Night	33% 7% 12% 23% 21% 3	1681
	11th to 20th	Night	24% 8% 15% 26% 24% 4	1600
	21st to end	Night	25% 7% 18% 24% 22% 5%	1600
July	1st to 10th	Night	32% 10% 21% 25% 10% 2	3580
	11th to 20th	Night	29% 9% 24% 30% 6% 1	3618
	21st to end	Night	41% 9% 23% 20% 6%	4658
August	1st to 10th	Night	16% 6% 13% 36% 27% 2	3232
	11th to 20th	Night	23% 8% 22% 28% 17% 2	3230
	21st to end	Night	27% 7% 14% 20% 26% 6%	3586
September	1st to 10th	Night	32% 7% 14% 22% 20% 7%	2000
	11th to 20th	Night	35% 6% 11% 18% 23% 6%	2111
	21st to end	Night	28% 6% 10% 23% 25% 9%	2200
October	1st to 10th	Night	17% 4 6% 16% 31% 27%	3590
	11th to 20th	Night	19% 2 4 15% 33% 26%	3881
	21st to end	Night	25% 3 5% 24% 27% 16%	4284
November	1st to 10th	Night	31% 4 9% 20% 26% 10%	2666
	11th to 20th	Night	31% 3 7% 20% 28% 10%	2730
	21st to end	Night	38% 3 8% 20% 24% 8%	2730
December	1st to 10th	Night	41% 3 5% 25% 23% 3	4380
	11th to 20th	Night	45% 3 5% 20% 24% 4	4954
	21st to end	Night	44% 3 10% 24% 15% 3	7132

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	24% 20% 32% 19% 6%	330
	11th to 20th	Day	24% 19% 37% 14% 4 2	318
	21st to end	Day	20% 18% 40% 19% 3	330
February	1st to 10th	Day	22% 18% 33% 16% 10% 1	300
	11th to 20th	Day	32% 18% 33% 13% 3 1	300
	21st to end	Day	31% 17% 38% 12% 3	249
March	1st to 10th	Day	26% 17% 31% 20% 6% 1	300
	11th to 20th	Day	18% 21% 36% 22% 3 1	300
	21st to end	Day	19% 15% 34% 24% 8% 1	543
April	1st to 10th	Day	17% 17% 28% 24% 12% 1	500
	11th to 20th	Day	18% 14% 28% 25% 12% 2	492
	21st to end	Day	16% 12% 23% 30% 15% 3	500
May	1st to 10th	Day	17% 9% 25% 27% 17% 4	503
	11th to 20th	Day	12% 7% 23% 27% 19% 12%	527
	21st to end	Day	10% 5% 19% 27% 25% 13%	573
June	1st to 10th	Day	11% 4 14% 28% 27% 16%	642
	11th to 20th	Day	7% 3 11% 27% 34% 17%	730
	21st to end	Day	9% 2 10% 25% 34% 20%	730
July	1st to 10th	Day	7% 2 8% 25% 36% 23%	721
	11th to 20th	Day	8% 2 6% 22% 33% 30%	718
	21st to end	Day	8% 2 6% 22% 35% 28%	632
August	1st to 10th	Day	6% 2 6% 21% 42% 23%	526
	11th to 20th	Day	9% 2 8% 25% 34% 21%	519
	21st to end	Day	12% 2 9% 19% 30% 27%	583
September	1st to 10th	Day	10% 2 8% 25% 39% 16%	530
	11th to 20th	Day	12% 2 10% 22% 33% 22%	530
	21st to end	Day	13% 4 12% 27% 31% 13%	530
October	1st to 10th	Day	9% 2 17% 30% 30% 12%	530
	11th to 20th	Day	9% 8% 26% 37% 17% 3	344
	21st to end	Day	21% 8% 24% 29% 15% 3	363
November	1st to 10th	Day	16% 10% 24% 28% 19% 3	330
	11th to 20th	Day	13% 10% 37% 29% 9% 2	330
	21st to end	Day	15% 19% 29% 21% 12% 3	330
December	1st to 10th	Day	24% 16% 32% 20% 7%	330
	11th to 20th	Day	20% 16% 33% 21% 9% 2	330
	21st to end	Day	23% 17% 33% 22% 5% 1	363
January	1st to 10th	Night	22% 12% 35% 26% 5%	1050
	11th to 20th	Night	25% 10% 33% 25% 7%	1031
	21st to end	Night	21% 9% 38% 29% 3	958
February	1st to 10th	Night	23% 10% 32% 30% 4	800
	11th to 20th	Night	25% 13% 31% 29% 3	783
	21st to end	Night	24% 11% 38% 25% 2	660
March	1st to 10th	Night	18% 12% 32% 32% 6%	800
	11th to 20th	Night	20% 8% 35% 30% 7%	715
	21st to end	Night	20% 8% 33% 29% 11%	660
April	1st to 10th	Night	15% 10% 32% 31% 12%	600
	11th to 20th	Night	14% 7% 30% 35% 13% 1	593
	21st to end	Night	14% 4 31% 36% 14% 1	600
May	1st to 10th	Night	13% 5% 25% 36% 19% 2	600
	11th to 20th	Night	13% 4 22% 34% 24% 4	591
	21st to end	Night	10% 1 13% 40% 31% 6%	650
June	1st to 10th	Night	7% 3 12% 37% 35% 7%	600
	11th to 20th	Night	5% 1 8% 34% 43% 9%	600
	21st to end	Night	5% 1 8% 30% 45% 11%	600
July	1st to 10th	Night	5% 1 5% 25% 51% 12%	585
	11th to 20th	Night	7% 1 4 22% 48% 18%	582
	21st to end	Night	6% 1 5% 24% 49% 14%	657
August	1st to 10th	Night	5% 5% 26% 51% 13%	597
	11th to 20th	Night	6% 1 4 30% 47% 12%	594
	21st to end	Night	8% 1 7% 25% 47% 11%	660
September	1st to 10th	Night	11% 1 8% 34% 42% 5%	600
	11th to 20th	Night	12% 2 11% 29% 41% 6%	711
	21st to end	Night	10% 3 13% 33% 38% 4	800
October	1st to 10th	Night	8% 3 13% 39% 33% 5%	800
	11th to 20th	Night	12% 4 20% 41% 21% 1	800
	21st to end	Night	19% 5% 20% 35% 20% 1	880
November	1st to 10th	Night	15% 4 20% 37% 21% 2	820
	11th to 20th	Night	12% 7% 31% 37% 12% 1	840
	21st to end	Night	19% 8% 27% 32% 13% 1	840
December	1st to 10th	Night	21% 9% 32% 30% 7%	840
	11th to 20th	Night	20% 8% 32% 31% 9%	840
	21st to end	Night	25% 9% 30% 29% 6%	1150

Page generated at 2026-01-14 00:14:32. Version ac07

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