Palm Coast
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Palm Coast clear sky chart from 2005-11-06 to 2025-05-11.

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% 5% 2 6% 5% 5% 5% 5% 7% 10% 41%	114172
	Night	10% 6% 2 6% 5% 4 5% 4 6% 9% 43%	114794
Transparency	Day	20% 44% 12% 12% 9% 3	117900
	Night	22% 43% 10% 12% 10% 4	119206
Seeing	Day	9% 3 13% 27% 31% 17%	16242
	Night	11% 4 16% 29% 31% 10%	26391

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	10% 5% 2 5% 3 3 3 3 5% 7% 53%	4056
	11th to 20th	Day	18% 11% 4 8% 4 4 4 3 4 6% 33%	4060
	21st to end	Day	15% 6% 2 5% 4 3 3 3 5% 7% 47%	4466
February	1st to 10th	Day	13% 8% 2 7% 4 4 4 4 6% 6% 42%	1980
	11th to 20th	Day	11% 5% 3 5% 4 4 3 3 5% 7% 49%	1948
	21st to end	Day	11% 5% 2 5% 3 4 5% 4 6% 7% 47%	1778
March	1st to 10th	Day	10% 7% 3 8% 4 5% 5% 4 5% 9% 40%	4935
	11th to 20th	Day	6% 3 2 4 2 3 3 3 5% 9% 61%	4980
	21st to end	Day	10% 6% 2 5% 3 4 4 4 6% 8% 47%	5465
April	1st to 10th	Day	8% 5% 1 5% 4 4 5% 4 5% 8% 51%	2200
	11th to 20th	Day	9% 4 2 6% 5% 4 5% 4 6% 8% 47%	2266
	21st to end	Day	6% 3 1 4 3 4 5% 4 7% 9% 54%	2400
May	1st to 10th	Day	4 2 1 3 3 3 4 4 6% 10% 60%	4130
	11th to 20th	Day	10% 4 2 7% 5% 6% 6% 5% 8% 8% 39%	4081
	21st to end	Day	5% 3 1 4 3 4 5% 4 8% 11% 51%	4476
June	1st to 10th	Day	10% 6% 3 7% 5% 5% 7% 5% 10% 12% 30%	2470
	11th to 20th	Day	5% 5% 2 7% 6% 6% 9% 6% 9% 12% 34%	2470
	21st to end	Day	9% 5% 3 8% 6% 6% 8% 5% 9% 11% 31%	2470
July	1st to 10th	Day	6% 5% 2 5% 5% 6% 7% 7% 11% 15% 32%	4120
	11th to 20th	Day	4 4 2 7% 6% 7% 8% 7% 11% 16% 29%	4120
	21st to end	Day	4 4 2 6% 6% 6% 7% 7% 10% 15% 33%	4466
August	1st to 10th	Day	6% 5% 2 8% 7% 7% 7% 6% 9% 12% 31%	4104
	11th to 20th	Day	4 4 2 6% 5% 6% 7% 6% 9% 13% 36%	3930
	21st to end	Day	8% 5% 2 7% 5% 6% 7% 6% 8% 14% 31%	3902
September	1st to 10th	Day	8% 7% 3 10% 7% 7% 8% 6% 10% 11% 23%	2090
	11th to 20th	Day	10% 6% 3 9% 7% 6% 8% 6% 9% 10% 26%	2090
	21st to end	Day	12% 6% 3 8% 6% 6% 7% 5% 7% 9% 32%	2090
October	1st to 10th	Day	14% 6% 3 7% 5% 5% 6% 5% 6% 9% 34%	2028
	11th to 20th	Day	7% 5% 2 5% 4 5% 5% 4 7% 8% 47%	1900
	21st to end	Day	10% 3 2 6% 3 4 5% 4 6% 9% 47%	2090
November	1st to 10th	Day	10% 5% 2 6% 4 4 6% 5% 7% 8% 43%	1957
	11th to 20th	Day	11% 7% 3 7% 4 5% 6% 5% 6% 7% 40%	2000
	21st to end	Day	11% 6% 3 7% 5% 5% 5% 4 5% 7% 42%	1885
December	1st to 10th	Day	6% 4 2 4 3 4 4 3 5% 8% 57%	2930
	11th to 20th	Day	11% 7% 3 7% 6% 5% 6% 4 7% 8% 36%	3373
	21st to end	Day	13% 7% 2 7% 5% 4 4 3 6% 7% 41%	4466
January	1st to 10th	Night	10% 5% 1 5% 3 2 3 3 4 7% 56%	5889
	11th to 20th	Night	20% 9% 3 7% 4 4 4 3 6% 8% 33%	5900
	21st to end	Night	16% 6% 2 6% 4 3 4 4 5% 8% 43%	6490
February	1st to 10th	Night	13% 6% 2 5% 5% 3 4 4 5% 6% 46%	2415
	11th to 20th	Night	11% 6% 2 5% 4 4 4 3 6% 6% 48%	2338
	21st to end	Night	9% 5% 2 5% 4 4 4 4 6% 7% 49%	1850
March	1st to 10th	Night	14% 8% 3 6% 4 4 4 4 5% 6% 43%	4918
	11th to 20th	Night	6% 4 1 4 3 3 4 3 5% 9% 56%	4980
	21st to end	Night	11% 5% 2 6% 4 4 4 4 5% 7% 48%	5467
April	1st to 10th	Night	8% 4 2 5% 4 4 4 4 6% 9% 50%	2200
	11th to 20th	Night	8% 5% 2 5% 4 4 4 4 6% 7% 50%	2080
	21st to end	Night	7% 3 2 4 3 3 4 4 7% 11% 52%	2000
May	1st to 10th	Night	3 2 1 3 3 3 5% 3 6% 10% 60%	3011
	11th to 20th	Night	9% 5% 2 6% 4 4 6% 5% 8% 10% 42%	2818
	21st to end	Night	4 3 1 3 3 4 4 4 6% 10% 58%	3079
June	1st to 10th	Night	10% 6% 2 5% 5% 5% 6% 5% 8% 12% 35%	1710
	11th to 20th	Night	5% 5% 3 5% 6% 5% 7% 6% 9% 12% 37%	1710
	21st to end	Night	7% 5% 2 7% 6% 5% 7% 5% 9% 12% 34%	1710
July	1st to 10th	Night	6% 5% 2 8% 5% 6% 6% 5% 10% 14% 34%	2840
	11th to 20th	Night	3 5% 2 5% 5% 5% 7% 6% 11% 16% 33%	2840
	21st to end	Night	5% 5% 3 7% 7% 7% 7% 6% 10% 13% 31%	3087
August	1st to 10th	Night	7% 6% 3 8% 6% 6% 6% 5% 9% 11% 33%	2825
	11th to 20th	Night	2 3 2 6% 6% 5% 7% 6% 9% 14% 40%	2866
	21st to end	Night	7% 6% 3 7% 5% 6% 5% 5% 8% 14% 35%	3748
September	1st to 10th	Night	9% 7% 3 9% 6% 7% 7% 6% 8% 10% 27%	2090
	11th to 20th	Night	12% 8% 4 8% 7% 6% 6% 5% 9% 10% 26%	2090
	21st to end	Night	11% 6% 3 8% 5% 6% 6% 5% 7% 8% 35%	2090
October	1st to 10th	Night	13% 6% 3 8% 5% 5% 5% 5% 7% 8% 35%	2152
	11th to 20th	Night	6% 4 2 5% 4 5% 5% 4 7% 9% 50%	2280
	21st to end	Night	9% 6% 2 6% 4 4 4 4 5% 7% 49%	2508
November	1st to 10th	Night	11% 6% 2 6% 5% 5% 4 4 6% 8% 43%	2341
	11th to 20th	Night	12% 6% 3 6% 5% 5% 5% 4 7% 7% 41%	2400
	21st to end	Night	11% 6% 2 5% 5% 5% 5% 4 6% 9% 42%	2510
December	1st to 10th	Night	7% 4 2 5% 4 4 3 3 5% 7% 56%	4250
	11th to 20th	Night	11% 8% 3 7% 5% 5% 5% 3 5% 7% 41%	4822
	21st to end	Night	14% 8% 3 8% 5% 4 4 4 6% 6% 38%	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	23% 27% 8% 10% 21% 10%	4057
	11th to 20th	Day	45% 27% 3 9% 10% 6%	4060
	21st to end	Day	25% 30% 7% 20% 12% 6%	4466
February	1st to 10th	Day	15% 63% 5% 6% 8% 3	1980
	11th to 20th	Day	12% 61% 5% 9% 10% 3	1958
	21st to end	Day	15% 62% 5% 7% 7% 4	1778
March	1st to 10th	Day	33% 33% 9% 10% 13% 2	4935
	11th to 20th	Day	13% 30% 9% 16% 20% 12%	4980
	21st to end	Day	24% 31% 9% 18% 12% 6%	5465
April	1st to 10th	Day	11% 63% 5% 11% 7% 3	2200
	11th to 20th	Day	11% 63% 3 10% 9% 3	2266
	21st to end	Day	9% 62% 6% 12% 11% 1	2400
May	1st to 10th	Day	8% 43% 16% 21% 8% 3	4167
	11th to 20th	Day	24% 46% 11% 15% 4 1	4085
	21st to end	Day	7% 43% 13% 27% 10% 1	4489
June	1st to 10th	Day	14% 69% 9% 6% 2	2470
	11th to 20th	Day	13% 68% 8% 9% 2	2470
	21st to end	Day	12% 67% 12% 6% 2	2470
July	1st to 10th	Day	17% 42% 29% 12% 1	4055
	11th to 20th	Day	18% 44% 34% 4	4051
	21st to end	Day	19% 44% 31% 6%	4324
August	1st to 10th	Day	27% 42% 23% 7% 1	4091
	11th to 20th	Day	16% 43% 21% 15% 4	3969
	21st to end	Day	20% 43% 20% 16% 1	3902
September	1st to 10th	Day	20% 65% 8% 3 3 1	2090
	11th to 20th	Day	18% 64% 9% 7% 2	2090
	21st to end	Day	16% 63% 8% 8% 5%	2090
October	1st to 10th	Day	38% 40% 9% 7% 6%	3366
	11th to 20th	Day	16% 38% 4 14% 21% 7%	3140
	21st to end	Day	11% 39% 6% 20% 22% 3	3428
November	1st to 10th	Day	17% 58% 7% 10% 6% 2	1957
	11th to 20th	Day	20% 58% 5% 7% 8% 3	2000
	21st to end	Day	18% 58% 4 10% 8% 3	1885
December	1st to 10th	Day	16% 36% 11% 18% 15% 4	2930
	11th to 20th	Day	29% 35% 7% 10% 15% 4	3370
	21st to end	Day	34% 28% 8% 17% 9% 3	4466
January	1st to 10th	Night	21% 27% 6% 14% 25% 8%	5889
	11th to 20th	Night	41% 27% 7% 11% 12% 2	5900
	21st to end	Night	28% 31% 7% 16% 12% 6%	6490
February	1st to 10th	Night	14% 62% 5% 8% 8% 3	2415
	11th to 20th	Night	14% 61% 4 10% 9% 2	2339
	21st to end	Night	14% 63% 6% 6% 8% 4	1850
March	1st to 10th	Night	33% 32% 7% 9% 11% 7%	4918
	11th to 20th	Night	15% 31% 10% 15% 14% 15%	4980
	21st to end	Night	26% 31% 8% 13% 15% 6%	5467
April	1st to 10th	Night	12% 64% 5% 11% 5% 3	2200
	11th to 20th	Night	12% 63% 3 10% 8% 3	2080
	21st to end	Night	10% 62% 7% 11% 8% 2	2000
May	1st to 10th	Night	8% 45% 18% 19% 7% 3	3040
	11th to 20th	Night	21% 48% 12% 15% 5%	2819
	21st to end	Night	6% 42% 12% 28% 11%	3087
June	1st to 10th	Night	14% 67% 12% 7% 1	1710
	11th to 20th	Night	13% 67% 10% 8% 2	1710
	21st to end	Night	14% 66% 9% 8% 3	1710
July	1st to 10th	Night	21% 41% 27% 12%	2795
	11th to 20th	Night	19% 46% 31% 4	2786
	21st to end	Night	28% 41% 26% 5%	2988
August	1st to 10th	Night	29% 39% 25% 7%	2814
	11th to 20th	Night	16% 42% 19% 17% 6%	2893
	21st to end	Night	21% 42% 22% 14% 1	3748
September	1st to 10th	Night	22% 63% 7% 4 3 1	2090
	11th to 20th	Night	17% 63% 9% 8% 3	2090
	21st to end	Night	16% 62% 7% 11% 4	2090
October	1st to 10th	Night	42% 39% 7% 6% 7%	3594
	11th to 20th	Night	19% 38% 3 11% 23% 5%	3779
	21st to end	Night	13% 38% 5% 17% 24% 3	4120
November	1st to 10th	Night	16% 58% 7% 10% 6% 2	2341
	11th to 20th	Night	19% 58% 4 8% 7% 4	2400
	21st to end	Night	17% 57% 4 10% 8% 4	2510
December	1st to 10th	Night	18% 35% 8% 20% 9% 10%	4250
	11th to 20th	Night	27% 34% 9% 14% 10% 6%	4824
	21st to end	Night	35% 31% 9% 13% 9% 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	11% 5% 27% 46% 11% 1	300
	11th to 20th	Day	9% 5% 30% 38% 16% 2	300
	21st to end	Day	16% 8% 30% 39% 7%	330
February	1st to 10th	Day	15% 9% 15% 38% 20% 3	300
	11th to 20th	Day	12% 4 22% 46% 14% 3	300
	21st to end	Day	12% 4 22% 39% 19% 3	377
March	1st to 10th	Day	9% 5% 27% 39% 18% 1	500
	11th to 20th	Day	12% 4 26% 36% 20% 4	500
	21st to end	Day	9% 5% 18% 42% 23% 3	550
April	1st to 10th	Day	9% 5% 22% 40% 22% 3	500
	11th to 20th	Day	7% 5% 20% 38% 24% 6%	492
	21st to end	Day	5% 3 14% 34% 34% 11%	500
May	1st to 10th	Day	4 2 13% 38% 35% 8%	503
	11th to 20th	Day	9% 2 10% 28% 36% 16%	487
	21st to end	Day	8% 1 5% 21% 42% 22%	529
June	1st to 10th	Day	10% 2 8% 23% 37% 21%	490
	11th to 20th	Day	4 2 6% 17% 43% 29%	490
	21st to end	Day	5% 2 3 14% 40% 36%	490
July	1st to 10th	Day	6% 1 5% 7% 35% 46%	485
	11th to 20th	Day	5% 1 2 4 40% 49%	484
	21st to end	Day	7% 5% 9% 40% 39%	532
August	1st to 10th	Day	6% 1 4 14% 39% 36%	486
	11th to 20th	Day	4 1 3 6% 38% 48%	479
	21st to end	Day	7% 2 5% 9% 40% 36%	539
September	1st to 10th	Day	10% 3 6% 10% 38% 33%	490
	11th to 20th	Day	11% 2 7% 17% 42% 22%	490
	21st to end	Day	11% 2 7% 16% 43% 21%	490
October	1st to 10th	Day	16% 2 13% 32% 29% 9%	490
	11th to 20th	Day	6% 2 11% 34% 38% 8%	490
	21st to end	Day	9% 4 11% 34% 34% 8%	539
November	1st to 10th	Day	11% 4 14% 32% 31% 7%	495
	11th to 20th	Day	14% 5% 17% 39% 20% 5%	500
	21st to end	Day	14% 4 22% 36% 21% 3	385
December	1st to 10th	Day	8% 4 24% 36% 23% 5%	300
	11th to 20th	Day	14% 5% 21% 35% 21% 3	300
	21st to end	Day	12% 4 18% 40% 21% 4	330
January	1st to 10th	Night	14% 9% 28% 35% 13% 1	800
	11th to 20th	Night	12% 7% 27% 35% 17% 2	800
	21st to end	Night	16% 8% 30% 34% 11% 1	880
February	1st to 10th	Night	15% 6% 23% 34% 21% 2	800
	11th to 20th	Night	14% 6% 26% 38% 15% 1	783
	21st to end	Night	12% 4 23% 44% 15% 2	660
March	1st to 10th	Night	7% 7% 25% 42% 18% 1	800
	11th to 20th	Night	10% 5% 22% 41% 19% 4	800
	21st to end	Night	9% 5% 21% 40% 23% 1	880
April	1st to 10th	Night	8% 4 24% 40% 22% 2	800
	11th to 20th	Night	9% 5% 19% 34% 30% 2	791
	21st to end	Night	7% 3 16% 39% 31% 4	800
May	1st to 10th	Night	5% 2 12% 40% 35% 5%	671
	11th to 20th	Night	8% 2 12% 29% 41% 9%	563
	21st to end	Night	7% 1 6% 26% 47% 13%	617
June	1st to 10th	Night	12% 1 6% 23% 45% 12%	570
	11th to 20th	Night	6% 2 4 19% 41% 27%	570
	21st to end	Night	6% 2 3 15% 50% 24%	570
July	1st to 10th	Night	7% 1 6% 11% 41% 34%	555
	11th to 20th	Night	6% 2 11% 45% 36%	552
	21st to end	Night	5% 2 3 12% 51% 28%	624
August	1st to 10th	Night	9% 4 10% 48% 29%	567
	11th to 20th	Night	3 3 10% 47% 35%	606
	21st to end	Night	11% 1 5% 10% 47% 26%	836
September	1st to 10th	Night	12% 1 5% 13% 43% 26%	760
	11th to 20th	Night	14% 2 6% 19% 43% 15%	760
	21st to end	Night	13% 1 7% 19% 42% 17%	760
October	1st to 10th	Night	16% 3 11% 28% 34% 9%	760
	11th to 20th	Night	8% 4 13% 33% 37% 7%	760
	21st to end	Night	11% 3 14% 29% 37% 5%	836
November	1st to 10th	Night	12% 4 17% 30% 32% 6%	780
	11th to 20th	Night	14% 5% 20% 35% 24% 4	800
	21st to end	Night	11% 6% 23% 37% 21% 3	800
December	1st to 10th	Night	11% 5% 23% 30% 26% 5%	800
	11th to 20th	Night	14% 7% 20% 31% 23% 5%	800
	21st to end	Night	15% 7% 19% 33% 24% 2	880

Page generated at 2025-05-08 09:33:54. Version ac07

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