Shallotte
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Shallotte 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	11% 6% 2 6% 5% 4 5% 4 6% 8% 42%	127172
	Night	11% 6% 2 6% 4 4 4 4 6% 8% 44%	124532
Transparency	Day	24% 41% 10% 12% 10% 4	130773
	Night	23% 40% 9% 12% 12% 4	128999
Seeing	Day	12% 5% 19% 29% 26% 9%	17354
	Night	13% 5% 21% 32% 23% 5%	27493

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	12% 5% 2 4 3 3 3 2 5% 7% 54%	4146
	11th to 20th	Day	11% 5% 2 5% 4 3 4 3 4 6% 53%	4114
	21st to end	Day	13% 9% 3 7% 4 4 4 3 5% 6% 43%	4466
February	1st to 10th	Day	15% 7% 2 7% 5% 4 4 3 6% 6% 41%	1800
	11th to 20th	Day	19% 6% 2 7% 4 3 3 3 4 5% 45%	1840
	21st to end	Day	13% 6% 3 6% 4 4 5% 3 5% 7% 44%	1801
March	1st to 10th	Day	20% 8% 3 7% 4 3 4 3 4 5% 38%	4935
	11th to 20th	Day	8% 4 2 5% 4 3 4 4 6% 6% 54%	4980
	21st to end	Day	11% 6% 3 6% 4 4 4 3 4 5% 50%	5465
April	1st to 10th	Day	9% 4 1 4 4 4 4 5% 6% 7% 52%	2335
	11th to 20th	Day	9% 5% 1 4 3 3 4 3 5% 8% 54%	2374
	21st to end	Day	7% 4 1 4 4 3 5% 4 6% 7% 55%	2400
May	1st to 10th	Day	7% 5% 3 7% 5% 5% 6% 5% 8% 11% 39%	5497
	11th to 20th	Day	15% 7% 3 8% 5% 5% 5% 4 7% 9% 33%	5861
	21st to end	Day	9% 5% 2 6% 5% 4 5% 5% 7% 10% 43%	6433
June	1st to 10th	Day	9% 7% 2 7% 5% 5% 6% 5% 8% 11% 34%	2600
	11th to 20th	Day	8% 5% 2 5% 4 5% 6% 5% 8% 12% 40%	2600
	21st to end	Day	7% 5% 2 6% 5% 5% 6% 6% 9% 12% 36%	2600
July	1st to 10th	Day	8% 6% 3 9% 6% 6% 7% 5% 8% 12% 29%	5900
	11th to 20th	Day	6% 5% 2 8% 6% 6% 7% 6% 9% 13% 32%	5900
	21st to end	Day	7% 7% 2 8% 6% 7% 7% 6% 9% 13% 30%	6424
August	1st to 10th	Day	21% 10% 4 9% 4 5% 5% 4 7% 10% 21%	4234
	11th to 20th	Day	7% 6% 2 7% 6% 4 6% 5% 9% 12% 36%	3899
	21st to end	Day	7% 6% 3 7% 5% 5% 5% 5% 7% 10% 41%	4312
September	1st to 10th	Day	10% 5% 2 7% 6% 5% 5% 5% 6% 10% 40%	2400
	11th to 20th	Day	14% 7% 2 6% 6% 5% 4 4 6% 9% 37%	2300
	21st to end	Day	15% 8% 3 7% 4 4 5% 4 4 7% 38%	2135
October	1st to 10th	Day	12% 5% 3 7% 5% 4 6% 4 5% 6% 45%	2000
	11th to 20th	Day	10% 4 2 5% 4 3 3 4 4 7% 57%	2000
	21st to end	Day	9% 5% 1 4 4 3 3 3 5% 5% 57%	2200
November	1st to 10th	Day	11% 5% 1 5% 3 3 3 4 4 5% 55%	2057
	11th to 20th	Day	11% 5% 2 5% 4 4 4 3 4 5% 52%	2100
	21st to end	Day	9% 6% 2 5% 5% 4 4 4 5% 6% 51%	2016
December	1st to 10th	Day	10% 5% 2 6% 4 4 4 4 5% 5% 52%	3020
	11th to 20th	Day	13% 7% 2 6% 4 4 4 3 5% 5% 46%	3463
	21st to end	Day	14% 7% 2 6% 4 4 4 3 6% 7% 45%	4565
January	1st to 10th	Night	10% 6% 2 5% 3 3 4 3 4 6% 54%	6019
	11th to 20th	Night	13% 6% 2 5% 4 4 4 4 5% 7% 47%	5979
	21st to end	Night	12% 8% 3 7% 5% 4 4 3 4 5% 46%	6490
February	1st to 10th	Night	15% 7% 3 7% 4 4 3 3 5% 6% 44%	2600
	11th to 20th	Night	18% 7% 2 6% 4 3 4 4 5% 6% 41%	2444
	21st to end	Night	14% 6% 2 7% 4 3 4 3 5% 7% 43%	1825
March	1st to 10th	Night	16% 10% 3 8% 4 4 4 3 4 5% 39%	4918
	11th to 20th	Night	12% 5% 2 5% 4 3 4 4 6% 8% 49%	4980
	21st to end	Night	12% 4 2 5% 4 4 4 3 4 6% 52%	5467
April	1st to 10th	Night	10% 6% 2 5% 4 4 4 4 5% 7% 48%	2064
	11th to 20th	Night	9% 5% 2 6% 4 4 5% 4 5% 6% 51%	1975
	21st to end	Night	6% 5% 2 5% 4 4 4 4 6% 7% 54%	2000
May	1st to 10th	Night	7% 5% 2 7% 5% 4 5% 4 7% 11% 42%	4426
	11th to 20th	Night	13% 7% 3 7% 4 5% 5% 4 6% 10% 36%	4032
	21st to end	Night	11% 6% 2 6% 4 4 5% 5% 7% 9% 41%	4421
June	1st to 10th	Night	10% 7% 3 8% 5% 5% 5% 4 8% 11% 35%	1800
	11th to 20th	Night	8% 5% 2 7% 5% 4 5% 4 8% 11% 41%	1800
	21st to end	Night	7% 4 2 7% 5% 6% 6% 5% 8% 13% 36%	1800
July	1st to 10th	Night	7% 5% 2 8% 6% 7% 7% 5% 9% 12% 31%	4058
	11th to 20th	Night	7% 6% 3 8% 5% 5% 7% 6% 10% 16% 29%	4057
	21st to end	Night	7% 6% 3 8% 6% 6% 7% 6% 10% 12% 30%	4427
August	1st to 10th	Night	20% 9% 3 7% 4 4 5% 5% 8% 11% 24%	2915
	11th to 20th	Night	6% 5% 2 8% 6% 5% 6% 5% 8% 12% 37%	3104
	21st to end	Night	6% 4 2 7% 5% 5% 6% 4 7% 10% 46%	3586
September	1st to 10th	Night	9% 5% 2 6% 5% 5% 5% 5% 7% 11% 40%	2000
	11th to 20th	Night	12% 6% 2 7% 5% 5% 5% 5% 8% 8% 38%	2095
	21st to end	Night	16% 8% 3 6% 4 3 4 4 4 7% 40%	2265
October	1st to 10th	Night	11% 6% 2 7% 4 5% 4 4 5% 7% 46%	2400
	11th to 20th	Night	10% 4 1 4 4 3 4 3 5% 6% 55%	2400
	21st to end	Night	9% 5% 2 5% 3 3 3 3 4 6% 55%	2640
November	1st to 10th	Night	10% 5% 2 6% 4 3 3 3 5% 6% 54%	2461
	11th to 20th	Night	10% 6% 3 6% 4 4 4 3 4 6% 50%	2520
	21st to end	Night	10% 5% 2 4 4 3 4 3 7% 7% 50%	2599
December	1st to 10th	Night	11% 5% 2 5% 4 3 3 3 4 6% 52%	4380
	11th to 20th	Night	14% 7% 3 7% 4 4 3 3 5% 5% 44%	4952
	21st to end	Night	13% 7% 3 6% 4 4 4 4 5% 6% 46%	6633

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	21% 27% 5% 13% 29% 6%	4147
	11th to 20th	Day	23% 27% 3 11% 27% 8%	4114
	21st to end	Day	30% 30% 5% 12% 15% 8%	4466
February	1st to 10th	Day	16% 63% 4 8% 7% 1	1800
	11th to 20th	Day	19% 61% 3 8% 7% 2	1849
	21st to end	Day	16% 62% 4 7% 7% 4	1801
March	1st to 10th	Day	38% 32% 5% 8% 12% 5%	4935
	11th to 20th	Day	16% 31% 6% 10% 23% 14%	4980
	21st to end	Day	25% 30% 7% 16% 14% 8%	5465
April	1st to 10th	Day	15% 63% 4 8% 8% 2	2335
	11th to 20th	Day	13% 63% 4 10% 6% 3	2374
	21st to end	Day	9% 62% 7% 12% 8% 1	2400
May	1st to 10th	Day	28% 35% 17% 16% 4 1	5529
	11th to 20th	Day	34% 33% 12% 15% 6%	5865
	21st to end	Day	24% 33% 13% 16% 13% 1	6447
June	1st to 10th	Day	15% 65% 8% 7% 5%	2600
	11th to 20th	Day	11% 65% 9% 10% 5%	2600
	21st to end	Day	13% 64% 13% 9% 1	2600
July	1st to 10th	Day	33% 34% 24% 9%	5835
	11th to 20th	Day	29% 34% 30% 6%	5831
	21st to end	Day	32% 33% 16% 14% 5%	6240
August	1st to 10th	Day	45% 39% 11% 4 1	4221
	11th to 20th	Day	22% 42% 15% 14% 6%	3936
	21st to end	Day	19% 39% 14% 25% 3	4312
September	1st to 10th	Day	15% 61% 9% 9% 6% 1	2400
	11th to 20th	Day	22% 58% 5% 8% 5% 2	2300
	21st to end	Day	22% 59% 8% 8% 3	2135
October	1st to 10th	Day	25% 38% 6% 15% 13% 3	3260
	11th to 20th	Day	9% 36% 3 10% 21% 22%	3240
	21st to end	Day	14% 38% 5% 15% 21% 7%	3538
November	1st to 10th	Day	17% 54% 5% 9% 12% 3	2057
	11th to 20th	Day	17% 55% 3 8% 13% 4	2100
	21st to end	Day	15% 54% 5% 10% 12% 3	2016
December	1st to 10th	Day	21% 36% 4 10% 18% 11%	3020
	11th to 20th	Day	28% 33% 6% 12% 17% 4	3460
	21st to end	Day	29% 29% 10% 17% 13% 1	4565
January	1st to 10th	Night	22% 28% 4 12% 28% 6%	6019
	11th to 20th	Night	26% 29% 4 10% 26% 5%	5979
	21st to end	Night	28% 30% 4 9% 21% 7%	6490
February	1st to 10th	Night	16% 62% 4 10% 7% 2	2600
	11th to 20th	Night	19% 62% 3 6% 8% 2	2446
	21st to end	Night	17% 62% 3 5% 9% 4	1825
March	1st to 10th	Night	38% 31% 5% 8% 15% 3	4918
	11th to 20th	Night	21% 30% 6% 8% 20% 15%	4980
	21st to end	Night	24% 30% 7% 17% 15% 7%	5467
April	1st to 10th	Night	14% 63% 5% 7% 8% 2	2064
	11th to 20th	Night	14% 63% 5% 10% 5% 3	1975
	21st to end	Night	11% 63% 5% 13% 6% 2	2000
May	1st to 10th	Night	25% 34% 16% 20% 5% 1	4456
	11th to 20th	Night	31% 34% 15% 14% 6%	4033
	21st to end	Night	26% 33% 13% 14% 14%	4429
June	1st to 10th	Night	14% 66% 8% 8% 4	1800
	11th to 20th	Night	10% 66% 10% 10% 4	1800
	21st to end	Night	12% 64% 11% 11% 2	1800
July	1st to 10th	Night	31% 34% 25% 11%	4015
	11th to 20th	Night	30% 35% 30% 5% 1	4006
	21st to end	Night	33% 34% 13% 17% 3	4297
August	1st to 10th	Night	40% 39% 15% 5% 1	2904
	11th to 20th	Night	20% 42% 17% 16% 5%	3132
	21st to end	Night	15% 40% 13% 27% 5%	3586
September	1st to 10th	Night	15% 59% 11% 9% 4 2	2000
	11th to 20th	Night	20% 59% 6% 9% 5% 1	2095
	21st to end	Night	20% 58% 9% 9% 4	2265
October	1st to 10th	Night	24% 38% 7% 13% 15% 3	3920
	11th to 20th	Night	8% 36% 3 8% 15% 30%	3899
	21st to end	Night	12% 37% 5% 19% 20% 8%	4252
November	1st to 10th	Night	19% 54% 4 8% 11% 4	2461
	11th to 20th	Night	17% 54% 4 8% 12% 5%	2520
	21st to end	Night	13% 55% 5% 12% 11% 3	2599
December	1st to 10th	Night	21% 35% 4 9% 21% 10%	4380
	11th to 20th	Night	30% 32% 8% 11% 14% 5%	4954
	21st to end	Night	29% 28% 9% 18% 15% 1	6633

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	13% 10% 38% 31% 7% 1	330
	11th to 20th	Day	10% 10% 32% 36% 9% 2	318
	21st to end	Day	18% 11% 33% 30% 7% 1	330
February	1st to 10th	Day	16% 10% 31% 33% 10%	300
	11th to 20th	Day	25% 8% 34% 27% 6%	387
	21st to end	Day	11% 12% 35% 31% 10% 1	414
March	1st to 10th	Day	14% 9% 30% 33% 12% 1	500
	11th to 20th	Day	17% 5% 37% 31% 8% 2	500
	21st to end	Day	12% 5% 37% 32% 12% 2	550
April	1st to 10th	Day	12% 11% 29% 30% 16% 2	500
	11th to 20th	Day	10% 7% 26% 28% 22% 6%	492
	21st to end	Day	6% 6% 20% 34% 26% 7%	500
May	1st to 10th	Day	5% 7% 28% 35% 19% 7%	503
	11th to 20th	Day	13% 3 14% 34% 28% 7%	527
	21st to end	Day	12% 4 12% 28% 30% 14%	573
June	1st to 10th	Day	10% 4 12% 31% 33% 10%	530
	11th to 20th	Day	10% 3 9% 26% 35% 17%	530
	21st to end	Day	6% 3 8% 27% 43% 13%	530
July	1st to 10th	Day	8% 3 4 20% 47% 18%	525
	11th to 20th	Day	7% 2 5% 22% 44% 20%	524
	21st to end	Day	7% 2 5% 26% 45% 15%	576
August	1st to 10th	Day	16% 3 7% 23% 37% 14%	526
	11th to 20th	Day	9% 2 6% 23% 36% 24%	519
	21st to end	Day	11% 3 7% 23% 37% 19%	583
September	1st to 10th	Day	10% 1 8% 26% 38% 17%	530
	11th to 20th	Day	15% 4 11% 25% 32% 13%	530
	21st to end	Day	18% 3 7% 27% 32% 14%	530
October	1st to 10th	Day	14% 3 17% 28% 26% 11%	530
	11th to 20th	Day	11% 2 19% 32% 28% 9%	530
	21st to end	Day	11% 5% 20% 30% 28% 6%	583
November	1st to 10th	Day	14% 3 21% 32% 24% 6%	535
	11th to 20th	Day	12% 5% 28% 35% 17% 1	540
	21st to end	Day	10% 6% 29% 30% 20% 4	456
December	1st to 10th	Day	20% 7% 23% 35% 14% 1	330
	11th to 20th	Day	16% 7% 25% 32% 17% 3	330
	21st to end	Day	16% 9% 27% 34% 10% 4	363
January	1st to 10th	Night	14% 11% 35% 32% 8%	840
	11th to 20th	Night	14% 10% 31% 35% 10%	825
	21st to end	Night	17% 8% 37% 34% 4	880
February	1st to 10th	Night	18% 7% 32% 35% 8%	800
	11th to 20th	Night	23% 11% 31% 32% 4	783
	21st to end	Night	18% 9% 30% 34% 10%	660
March	1st to 10th	Night	15% 7% 35% 33% 10%	800
	11th to 20th	Night	14% 8% 28% 39% 10% 1	800
	21st to end	Night	13% 6% 32% 35% 13% 1	880
April	1st to 10th	Night	12% 8% 31% 34% 15% 1	800
	11th to 20th	Night	10% 7% 25% 31% 23% 3	791
	21st to end	Night	8% 5% 24% 37% 24% 3	800
May	1st to 10th	Night	7% 5% 23% 39% 22% 3	775
	11th to 20th	Night	13% 4 19% 31% 29% 4	591
	21st to end	Night	12% 1 9% 28% 35% 15%	650
June	1st to 10th	Night	12% 3 11% 33% 36% 6%	600
	11th to 20th	Night	10% 2 9% 30% 38% 12%	600
	21st to end	Night	8% 3 7% 31% 39% 12%	600
July	1st to 10th	Night	9% 3 6% 24% 47% 12%	585
	11th to 20th	Night	9% 1 4 24% 47% 15%	582
	21st to end	Night	7% 3 4 28% 44% 13%	657
August	1st to 10th	Night	13% 2 6% 24% 42% 13%	597
	11th to 20th	Night	10% 2 5% 27% 43% 14%	733
	21st to end	Night	12% 2 5% 24% 43% 15%	880
September	1st to 10th	Night	10% 2 7% 28% 40% 12%	800
	11th to 20th	Night	14% 3 7% 31% 36% 9%	800
	21st to end	Night	20% 2 11% 26% 32% 10%	800
October	1st to 10th	Night	13% 3 17% 30% 28% 9%	800
	11th to 20th	Night	11% 3 21% 34% 24% 6%	800
	21st to end	Night	12% 6% 19% 31% 26% 5%	880
November	1st to 10th	Night	14% 4 22% 36% 21% 4	820
	11th to 20th	Night	13% 7% 29% 33% 16% 2	840
	21st to end	Night	11% 5% 29% 34% 18% 2	840
December	1st to 10th	Night	19% 7% 27% 33% 13% 1	840
	11th to 20th	Night	16% 8% 28% 32% 15% 1	840
	21st to end	Night	17% 7% 30% 32% 12% 1	924

Page generated at 2026-01-14 01:14:31. Version ac07

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