Blue Springs Camp
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Blue Springs Camp clear sky chart from 2005-11-06 to 2025-08-05.

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	14% 11% 4 9% 6% 5% 5% 4 5% 7% 31%	126473
	Night	14% 10% 4 10% 5% 5% 5% 4 5% 6% 32%	121565
Transparency	Day	50% 6% 13% 20% 11% 1	130068
	Night	48% 6% 13% 20% 12% 1	126059
Seeing	Day	20% 18% 31% 20% 9% 3	15741
	Night	19% 17% 31% 23% 9% 1	24779

By Month

Percentage Cloud Cover NE (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	11% 15% 7% 17% 7% 5% 4 2 3 5% 23%	3597
	11th to 20th	Day	9% 20% 9% 22% 8% 6% 4 4 5% 4 9%	4026
	21st to end	Day	16% 16% 7% 18% 8% 5% 4 2 4 4 15%	4466
February	1st to 10th	Day	13% 18% 5% 16% 10% 5% 4 4 5% 4 17%	1800
	11th to 20th	Day	13% 14% 6% 14% 9% 5% 4 3 5% 6% 21%	1753
	21st to end	Day	17% 14% 6% 12% 7% 4 6% 3 3 5% 23%	1565
March	1st to 10th	Day	17% 11% 5% 12% 7% 4 4 3 4 5% 29%	4922
	11th to 20th	Day	11% 13% 5% 9% 5% 5% 5% 4 6% 8% 29%	4980
	21st to end	Day	17% 13% 5% 9% 4 4 4 4 5% 5% 30%	5465
April	1st to 10th	Day	17% 15% 4 9% 5% 5% 3 4 4 7% 28%	2333
	11th to 20th	Day	18% 10% 2 8% 5% 4 4 3 4 6% 35%	2487
	21st to end	Day	19% 10% 3 8% 5% 4 5% 3 5% 6% 32%	2600
May	1st to 10th	Day	19% 9% 3 8% 4 4 4 3 5% 7% 33%	5888
	11th to 20th	Day	16% 10% 4 9% 5% 4 5% 4 5% 7% 32%	6170
	21st to end	Day	17% 7% 2 7% 4 4 5% 4 5% 7% 38%	6949
June	1st to 10th	Day	14% 6% 2 7% 5% 4 5% 4 6% 8% 37%	2800
	11th to 20th	Day	12% 6% 2 8% 5% 5% 5% 4 7% 9% 38%	2866
	21st to end	Day	14% 6% 2 6% 6% 5% 5% 5% 6% 8% 38%	3000
July	1st to 10th	Day	9% 5% 2 7% 5% 4 5% 5% 7% 10% 40%	6681
	11th to 20th	Day	7% 5% 2 6% 5% 5% 5% 4 7% 10% 44%	6275
	21st to end	Day	8% 4 2 6% 4 5% 5% 4 7% 9% 46%	6424
August	1st to 10th	Day	17% 7% 2 6% 4 4 5% 4 7% 9% 36%	4156
	11th to 20th	Day	11% 7% 3 8% 6% 5% 6% 4 7% 10% 32%	4044
	21st to end	Day	9% 6% 2 7% 5% 5% 6% 4 7% 9% 40%	4404
September	1st to 10th	Day	12% 6% 2 7% 5% 5% 5% 4 5% 8% 40%	2280
	11th to 20th	Day	12% 7% 2 6% 4 4 4 4 5% 9% 43%	2124
	21st to end	Day	15% 8% 2 7% 6% 5% 5% 4 5% 8% 34%	2077
October	1st to 10th	Day	18% 10% 3 8% 5% 4 4 3 5% 6% 33%	1900
	11th to 20th	Day	21% 10% 4 9% 5% 5% 4 4 5% 5% 29%	1900
	21st to end	Day	23% 14% 4 8% 5% 4 5% 3 5% 6% 22%	2090
November	1st to 10th	Day	14% 12% 4 8% 6% 6% 4 4 6% 6% 30%	1705
	11th to 20th	Day	14% 16% 4 9% 5% 5% 6% 3 6% 6% 25%	1600
	21st to end	Day	17% 17% 7% 9% 7% 5% 5% 3 5% 6% 19%	1600
December	1st to 10th	Day	16% 21% 8% 14% 7% 5% 4 4 5% 5% 12%	2600
	11th to 20th	Day	21% 20% 5% 10% 7% 5% 4 3 4 5% 17%	2986
	21st to end	Day	24% 20% 6% 14% 7% 5% 4 3 3 3 11%	3960
January	1st to 10th	Night	13% 13% 5% 13% 8% 5% 5% 4 5% 6% 22%	6333
	11th to 20th	Night	11% 13% 7% 17% 11% 9% 8% 5% 6% 4 11%	5859
	21st to end	Night	14% 13% 7% 14% 7% 5% 6% 4 6% 6% 18%	6490
February	1st to 10th	Night	13% 15% 5% 12% 7% 6% 6% 4 5% 7% 20%	2600
	11th to 20th	Night	13% 13% 5% 13% 8% 5% 5% 4 5% 6% 24%	2533
	21st to end	Night	13% 13% 5% 11% 6% 4 5% 5% 6% 7% 25%	2063
March	1st to 10th	Night	14% 10% 4 10% 5% 5% 5% 4 6% 6% 31%	4916
	11th to 20th	Night	9% 8% 4 8% 5% 5% 5% 4 7% 8% 36%	4979
	21st to end	Night	18% 9% 3 7% 4 4 4 3 5% 5% 38%	5467
April	1st to 10th	Night	19% 11% 4 7% 5% 4 4 4 5% 7% 30%	2066
	11th to 20th	Night	15% 10% 3 7% 6% 5% 4 3 5% 6% 37%	1877
	21st to end	Night	15% 10% 3 7% 5% 4 5% 4 5% 6% 36%	1800
May	1st to 10th	Night	19% 8% 2 7% 4 4 5% 3 5% 6% 36%	4053
	11th to 20th	Night	13% 9% 3 8% 5% 5% 4 4 5% 6% 37%	3721
	21st to end	Night	17% 6% 2 5% 4 3 4 3 5% 8% 43%	3926
June	1st to 10th	Night	11% 6% 2 6% 5% 4 4 5% 7% 8% 43%	1600
	11th to 20th	Night	10% 6% 2 6% 4 4 5% 5% 8% 8% 42%	1526
	21st to end	Night	11% 6% 3 7% 4 3 4 4 5% 7% 47%	1400
July	1st to 10th	Night	6% 6% 2 5% 4 4 4 4 6% 9% 48%	3287
	11th to 20th	Night	9% 4 2 6% 4 3 4 3 5% 8% 50%	3682
	21st to end	Night	7% 5% 2 6% 3 4 4 4 6% 8% 52%	4428
August	1st to 10th	Night	10% 5% 2 7% 4 4 4 3 5% 7% 47%	2861
	11th to 20th	Night	11% 6% 2 5% 3 4 4 4 6% 8% 47%	2785
	21st to end	Night	10% 5% 2 6% 4 4 4 4 5% 7% 48%	3220
September	1st to 10th	Night	10% 5% 2 5% 5% 4 4 4 6% 7% 47%	1900
	11th to 20th	Night	10% 5% 2 4 4 3 3 3 5% 7% 54%	2052
	21st to end	Night	16% 8% 3 7% 5% 4 4 4 5% 6% 40%	2102
October	1st to 10th	Night	15% 7% 3 7% 4 4 4 3 5% 7% 40%	2280
	11th to 20th	Night	17% 10% 3 8% 5% 5% 5% 4 5% 6% 34%	2280
	21st to end	Night	19% 10% 3 9% 5% 5% 4 4 5% 6% 29%	2508
November	1st to 10th	Night	14% 9% 3 7% 5% 5% 4 4 5% 7% 37%	2587
	11th to 20th	Night	14% 13% 3 10% 5% 5% 5% 5% 6% 7% 26%	2800
	21st to end	Night	18% 12% 5% 10% 6% 4 5% 4 6% 7% 24%	2800
December	1st to 10th	Night	13% 15% 8% 15% 7% 6% 6% 4 5% 6% 14%	4580
	11th to 20th	Night	15% 20% 6% 13% 6% 6% 5% 3 4 4 17%	5208
	21st to end	Night	23% 20% 7% 13% 6% 5% 4 3 4 4 12%	6996

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	61% 6% 11% 10% 10% 1	3598
	11th to 20th	Day	74% 4 9% 9% 4	4060
	21st to end	Day	70% 5% 11% 8% 6%	4466
February	1st to 10th	Day	66% 8% 9% 13% 4 1	1800
	11th to 20th	Day	62% 6% 9% 14% 7% 2	1762
	21st to end	Day	61% 6% 11% 14% 7% 1	1565
March	1st to 10th	Day	56% 5% 14% 14% 11% 1	4925
	11th to 20th	Day	50% 5% 17% 18% 6% 3	4980
	21st to end	Day	52% 6% 11% 19% 11% 1	5465
April	1st to 10th	Day	55% 6% 11% 17% 11% 1	2333
	11th to 20th	Day	49% 6% 10% 20% 13% 1	2487
	21st to end	Day	51% 6% 11% 18% 12% 3	2600
May	1st to 10th	Day	49% 5% 13% 17% 10% 6%	5897
	11th to 20th	Day	49% 7% 11% 17% 14% 1	6174
	21st to end	Day	44% 6% 12% 21% 14% 3	6949
June	1st to 10th	Day	42% 8% 11% 22% 16% 1	2800
	11th to 20th	Day	39% 7% 15% 24% 14% 1	2866
	21st to end	Day	40% 7% 14% 23% 15%	3000
July	1st to 10th	Day	37% 5% 15% 25% 16% 2	6611
	11th to 20th	Day	32% 5% 14% 31% 16% 1	6200
	21st to end	Day	33% 6% 15% 29% 17% 1	6240
August	1st to 10th	Day	43% 7% 13% 23% 13% 1	4143
	11th to 20th	Day	43% 8% 16% 24% 9%	4083
	21st to end	Day	37% 7% 15% 31% 9% 1	4404
September	1st to 10th	Day	41% 7% 14% 26% 11% 1	2280
	11th to 20th	Day	36% 7% 13% 29% 14%	2124
	21st to end	Day	47% 8% 13% 23% 8% 1	2077
October	1st to 10th	Day	43% 5% 13% 25% 13% 1	3160
	11th to 20th	Day	43% 4 14% 21% 16%	3140
	21st to end	Day	55% 5% 13% 20% 7%	3428
November	1st to 10th	Day	50% 7% 13% 21% 8% 1	1705
	11th to 20th	Day	55% 8% 15% 14% 8%	1600
	21st to end	Day	62% 8% 13% 13% 4	1600
December	1st to 10th	Day	69% 6% 13% 9% 3	2600
	11th to 20th	Day	67% 5% 11% 10% 6%	2986
	21st to end	Day	76% 6% 6% 7% 5%	3960
January	1st to 10th	Night	55% 7% 11% 17% 8% 1	6333
	11th to 20th	Night	68% 7% 10% 11% 4	5900
	21st to end	Night	62% 5% 11% 13% 8% 1	6490
February	1st to 10th	Night	59% 8% 11% 16% 5% 1	2600
	11th to 20th	Night	58% 5% 12% 16% 8%	2535
	21st to end	Night	54% 8% 12% 17% 8%	2063
March	1st to 10th	Night	48% 5% 15% 17% 11% 2	4926
	11th to 20th	Night	41% 5% 21% 21% 11% 2	4980
	21st to end	Night	46% 4 11% 19% 18% 2	5467
April	1st to 10th	Night	53% 5% 9% 17% 14% 1	2066
	11th to 20th	Night	47% 6% 10% 20% 16% 2	1877
	21st to end	Night	45% 6% 11% 19% 16% 2	1800
May	1st to 10th	Night	48% 5% 12% 15% 13% 7%	4060
	11th to 20th	Night	44% 7% 14% 20% 12% 3	3722
	21st to end	Night	38% 6% 14% 24% 16% 2	3927
June	1st to 10th	Night	36% 7% 12% 26% 18% 1	1600
	11th to 20th	Night	36% 6% 13% 25% 18% 2	1526
	21st to end	Night	36% 6% 14% 27% 17% 1	1400
July	1st to 10th	Night	31% 4 16% 25% 21% 3	3250
	11th to 20th	Night	31% 4 13% 30% 20% 2	3634
	21st to end	Night	30% 6% 13% 30% 20% 2	4297
August	1st to 10th	Night	36% 5% 13% 28% 16% 3	2850
	11th to 20th	Night	33% 6% 16% 31% 12% 1	2812
	21st to end	Night	34% 5% 13% 32% 15% 1	3220
September	1st to 10th	Night	33% 8% 14% 29% 15% 1	1900
	11th to 20th	Night	29% 6% 11% 33% 20% 1	2052
	21st to end	Night	43% 6% 12% 27% 11% 1	2102
October	1st to 10th	Night	34% 5% 9% 27% 24% 1	3800
	11th to 20th	Night	45% 5% 11% 24% 15%	3779
	21st to end	Night	42% 5% 15% 26% 11% 1	4120
November	1st to 10th	Night	44% 7% 13% 22% 12% 1	2587
	11th to 20th	Night	52% 8% 14% 16% 8% 1	2800
	21st to end	Night	54% 9% 17% 14% 5%	2800
December	1st to 10th	Night	63% 7% 16% 11% 3	4580
	11th to 20th	Night	64% 6% 10% 13% 6%	5208
	21st to end	Night	73% 6% 9% 8% 4	6996

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	22% 28% 32% 15% 3 1	200
	11th to 20th	Day	24% 33% 29% 12% 2	300
	21st to end	Day	25% 29% 32% 12% 2	330
February	1st to 10th	Day	26% 34% 28% 10% 2	300
	11th to 20th	Day	27% 33% 34% 7%	300
	21st to end	Day	36% 27% 33% 4	249
March	1st to 10th	Day	24% 23% 33% 16% 4	490
	11th to 20th	Day	24% 24% 35% 13% 4	500
	21st to end	Day	30% 19% 31% 15% 4 1	550
April	1st to 10th	Day	23% 27% 31% 12% 6%	500
	11th to 20th	Day	30% 21% 27% 14% 6% 2	492
	21st to end	Day	26% 18% 34% 15% 6% 2	500
May	1st to 10th	Day	23% 17% 31% 17% 8% 3	503
	11th to 20th	Day	16% 15% 33% 22% 11% 3	527
	21st to end	Day	14% 13% 32% 24% 12% 4	573
June	1st to 10th	Day	15% 16% 36% 25% 7% 2	530
	11th to 20th	Day	13% 15% 29% 29% 11% 2	596
	21st to end	Day	16% 12% 34% 27% 8% 2	730
July	1st to 10th	Day	9% 7% 31% 32% 16% 5%	664
	11th to 20th	Day	11% 8% 31% 26% 16% 6%	524
	21st to end	Day	9% 7% 35% 31% 14% 5%	576
August	1st to 10th	Day	12% 6% 29% 28% 18% 7%	502
	11th to 20th	Day	10% 8% 27% 27% 19% 9%	479
	21st to end	Day	14% 8% 27% 28% 17% 6%	539
September	1st to 10th	Day	12% 14% 25% 25% 16% 8%	490
	11th to 20th	Day	10% 7% 24% 26% 21% 12%	490
	21st to end	Day	18% 14% 26% 22% 14% 5%	490
October	1st to 10th	Day	23% 18% 27% 18% 12% 3	490
	11th to 20th	Day	23% 21% 34% 13% 7% 1	490
	21st to end	Day	29% 20% 29% 16% 5%	539
November	1st to 10th	Day	24% 24% 32% 15% 4 1	278
	11th to 20th	Day	23% 30% 30% 11% 5% 1	200
	21st to end	Day	27% 25% 37% 11% 1	200
December	1st to 10th	Day	32% 31% 25% 13% 1	200
	11th to 20th	Day	31% 30% 30% 9% 1	200
	21st to end	Day	30% 30% 27% 11% 1 1	220
January	1st to 10th	Night	21% 29% 34% 13% 3	800
	11th to 20th	Night	26% 24% 32% 16% 2	800
	21st to end	Night	18% 22% 37% 18% 5%	880
February	1st to 10th	Night	20% 31% 31% 17% 2	800
	11th to 20th	Night	22% 24% 34% 16% 3	783
	21st to end	Night	20% 27% 35% 17% 3	660
March	1st to 10th	Night	20% 21% 37% 18% 4	800
	11th to 20th	Night	21% 22% 35% 17% 5%	800
	21st to end	Night	21% 18% 34% 21% 6%	880
April	1st to 10th	Night	23% 18% 35% 21% 3	800
	11th to 20th	Night	20% 17% 35% 19% 8% 1	693
	21st to end	Night	19% 14% 34% 25% 9%	600
May	1st to 10th	Night	17% 12% 31% 27% 11% 2	600
	11th to 20th	Night	15% 9% 31% 30% 13% 1	462
	21st to end	Night	13% 8% 29% 34% 15%	433
June	1st to 10th	Night	12% 9% 34% 34% 11% 1	400
	11th to 20th	Night	12% 8% 33% 35% 12% 1	400
	21st to end	Night	12% 7% 31% 38% 12%	400
July	1st to 10th	Night	6% 5% 28% 42% 18% 1	390
	11th to 20th	Night	9% 5% 31% 35% 18% 1	418
	21st to end	Night	9% 3 28% 38% 19% 2	657
August	1st to 10th	Night	9% 2 26% 37% 23% 2	579
	11th to 20th	Night	8% 5% 21% 38% 25% 3	564
	21st to end	Night	14% 5% 27% 30% 22% 2	684
September	1st to 10th	Night	12% 9% 26% 31% 18% 4	760
	11th to 20th	Night	12% 7% 24% 28% 24% 6%	760
	21st to end	Night	19% 12% 21% 26% 18% 4	760
October	1st to 10th	Night	19% 11% 31% 23% 14% 3	760
	11th to 20th	Night	21% 18% 29% 23% 8% 1	760
	21st to end	Night	24% 19% 32% 21% 4	836
November	1st to 10th	Night	21% 17% 29% 24% 8% 1	780
	11th to 20th	Night	21% 23% 30% 20% 5% 1	800
	21st to end	Night	22% 23% 33% 17% 4	800
December	1st to 10th	Night	26% 25% 31% 13% 5%	800
	11th to 20th	Night	23% 26% 35% 13% 3	800
	21st to end	Night	28% 24% 28% 17% 2	880

Page generated at 2025-08-02 01:32:27. Version ac07

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