Lemon Lake County Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lemon Lake County Park clear sky chart from 2005-11-06 to 2025-12-18.

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	13% 9% 3 8% 5% 5% 5% 4 6% 7% 36%	126962
	Night	14% 10% 4 8% 5% 4 4 3 5% 6% 37%	124295
Transparency	Day	45% 6% 12% 22% 13% 2	130500
	Night	46% 5% 11% 21% 15% 2	128818
Seeing	Day	16% 11% 30% 25% 13% 5%	17274
	Night	17% 10% 31% 29% 12% 1	27126

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% 11% 9% 14% 6% 4 5% 4 6% 6% 21%	3617
	11th to 20th	Day	12% 13% 7% 14% 6% 6% 4 6% 6% 4 23%	3620
	21st to end	Day	18% 19% 5% 9% 4 3 3 3 4 5% 26%	4046
February	1st to 10th	Day	16% 14% 5% 9% 7% 6% 3 3 5% 6% 26%	1905
	11th to 20th	Day	14% 12% 4 9% 6% 5% 4 3 5% 7% 32%	1948
	21st to end	Day	15% 13% 5% 10% 5% 3 4 4 5% 6% 28%	1650
March	1st to 10th	Day	19% 13% 3 7% 4 3 3 3 4 5% 38%	4480
	11th to 20th	Day	8% 8% 4 7% 5% 5% 5% 4 6% 7% 40%	4657
	21st to end	Day	19% 13% 6% 11% 6% 5% 5% 4 5% 5% 21%	5939
April	1st to 10th	Day	17% 13% 3 7% 5% 4 4 4 5% 6% 31%	2400
	11th to 20th	Day	16% 10% 3 7% 5% 4 4 4 5% 7% 37%	2374
	21st to end	Day	20% 7% 3 8% 4 5% 4 4 6% 7% 33%	2535
May	1st to 10th	Day	19% 8% 2 7% 5% 5% 5% 4 6% 9% 31%	5862
	11th to 20th	Day	14% 6% 2 7% 4 5% 5% 4 6% 8% 40%	5991
	21st to end	Day	14% 6% 2 6% 4 4 5% 4 5% 9% 40%	6935
June	1st to 10th	Day	11% 5% 2 6% 4 5% 6% 4 6% 8% 44%	2800
	11th to 20th	Day	9% 5% 2 6% 4 5% 5% 4 6% 9% 45%	2800
	21st to end	Day	10% 6% 2 6% 5% 5% 6% 5% 7% 9% 40%	2800
July	1st to 10th	Day	10% 6% 3 7% 5% 6% 6% 5% 8% 10% 36%	6360
	11th to 20th	Day	9% 5% 2 6% 5% 5% 5% 4 7% 11% 40%	6360
	21st to end	Day	10% 7% 3 7% 4 5% 5% 4 7% 9% 39%	6924
August	1st to 10th	Day	7% 5% 2 6% 4 5% 5% 4 6% 8% 48%	4368
	11th to 20th	Day	9% 5% 2 6% 4 5% 4 5% 6% 8% 45%	3920
	21st to end	Day	7% 4 2 5% 5% 5% 5% 4 6% 9% 49%	4312
September	1st to 10th	Day	10% 5% 2 5% 4 5% 4 3 6% 7% 49%	2400
	11th to 20th	Day	10% 5% 1 5% 3 4 4 3 6% 8% 50%	2237
	21st to end	Day	11% 6% 2 6% 4 4 4 5% 6% 8% 44%	2200
October	1st to 10th	Day	11% 7% 3 6% 4 4 4 4 4 7% 46%	2200
	11th to 20th	Day	18% 8% 2 7% 4 4 4 4 5% 7% 37%	1964
	21st to end	Day	19% 9% 3 8% 4 5% 4 4 5% 6% 33%	1980
November	1st to 10th	Day	12% 8% 2 6% 4 4 4 4 5% 8% 44%	1852
	11th to 20th	Day	18% 9% 3 9% 4 4 3 3 5% 7% 35%	1890
	21st to end	Day	17% 13% 3 9% 5% 4 4 3 5% 5% 34%	1890
December	1st to 10th	Day	9% 12% 4 8% 5% 4 4 3 5% 6% 39%	2700
	11th to 20th	Day	13% 16% 5% 12% 6% 5% 5% 4 6% 7% 23%	3064
	21st to end	Day	25% 22% 6% 12% 5% 4 4 3 4 4 10%	3982
January	1st to 10th	Night	14% 15% 8% 12% 6% 4 4 3 5% 5% 25%	6348
	11th to 20th	Night	14% 16% 7% 13% 6% 5% 5% 4 5% 4 20%	6360
	21st to end	Night	19% 15% 6% 8% 4 4 3 3 4 3 31%	6929
February	1st to 10th	Night	16% 14% 5% 8% 6% 4 4 3 4 6% 30%	2493
	11th to 20th	Night	14% 11% 4 8% 5% 4 4 3 4 7% 35%	2338
	21st to end	Night	19% 12% 4 8% 4 3 3 3 5% 5% 34%	1980
March	1st to 10th	Night	16% 11% 4 7% 4 4 3 3 4 5% 39%	5373
	11th to 20th	Night	12% 7% 2 6% 4 4 4 3 5% 7% 46%	5302
	21st to end	Night	17% 10% 6% 9% 5% 5% 5% 4 6% 6% 29%	5018
April	1st to 10th	Night	15% 9% 3 7% 5% 4 5% 3 6% 7% 38%	2000
	11th to 20th	Night	17% 9% 3 7% 4 4 4 3 4 7% 38%	1975
	21st to end	Night	17% 7% 3 7% 5% 5% 4 3 5% 6% 37%	1865
May	1st to 10th	Night	19% 9% 3 7% 4 5% 4 3 5% 7% 33%	4033
	11th to 20th	Night	14% 7% 3 5% 4 3 4 4 6% 8% 42%	3905
	21st to end	Night	15% 8% 3 7% 5% 4 4 3 5% 7% 39%	3942
June	1st to 10th	Night	9% 5% 2 6% 4 4 4 4 5% 9% 49%	1600
	11th to 20th	Night	8% 7% 2 6% 5% 5% 4 4 6% 9% 45%	1600
	21st to end	Night	10% 6% 2 6% 6% 4 5% 5% 6% 8% 43%	1600
July	1st to 10th	Night	9% 5% 2 6% 5% 5% 5% 4 6% 8% 44%	3618
	11th to 20th	Night	7% 5% 2 6% 4 4 4 4 6% 8% 49%	3617
	21st to end	Night	8% 6% 2 7% 5% 5% 5% 4 6% 8% 44%	3947
August	1st to 10th	Night	7% 4 2 6% 4 4 6% 4 6% 10% 48%	2783
	11th to 20th	Night	8% 5% 2 5% 4 4 5% 4 5% 8% 51%	3126
	21st to end	Night	8% 5% 2 5% 4 3 4 4 5% 8% 52%	3586
September	1st to 10th	Night	10% 5% 3 5% 4 3 3 3 5% 6% 53%	2000
	11th to 20th	Night	8% 4 1 4 3 3 4 4 6% 7% 55%	2141
	21st to end	Night	10% 6% 3 6% 4 5% 4 4 5% 8% 47%	2200
October	1st to 10th	Night	11% 4 2 5% 4 4 3 3 5% 7% 52%	2200
	11th to 20th	Night	16% 7% 3 6% 3 4 3 3 5% 6% 45%	2432
	21st to end	Night	20% 8% 2 7% 4 4 4 3 4 7% 38%	2860
November	1st to 10th	Night	13% 8% 3 6% 4 4 4 3 5% 7% 44%	2666
	11th to 20th	Night	15% 9% 3 8% 4 4 4 4 5% 7% 37%	2730
	21st to end	Night	18% 11% 3 8% 5% 4 4 3 4 5% 35%	2730
December	1st to 10th	Night	13% 10% 3 7% 4 4 4 3 4 6% 42%	4704
	11th to 20th	Night	17% 13% 4 9% 5% 5% 4 4 4 5% 29%	5298
	21st to end	Night	24% 19% 6% 11% 5% 4 4 3 4 4 16%	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	60% 7% 10% 14% 7% 1	3618
	11th to 20th	Day	63% 4 9% 9% 12% 4	3620
	21st to end	Day	62% 3 11% 16% 7%	4046
February	1st to 10th	Day	61% 3 13% 14% 8% 2	1905
	11th to 20th	Day	53% 5% 10% 22% 10% 1	1958
	21st to end	Day	55% 7% 10% 19% 7% 2	1650
March	1st to 10th	Day	50% 5% 8% 23% 11% 3	4480
	11th to 20th	Day	41% 5% 12% 32% 10% 1	4657
	21st to end	Day	63% 7% 12% 12% 5% 1	5941
April	1st to 10th	Day	52% 5% 11% 20% 12%	2400
	11th to 20th	Day	47% 6% 11% 22% 12% 3	2374
	21st to end	Day	50% 6% 14% 18% 11% 2	2535
May	1st to 10th	Day	48% 7% 11% 20% 12% 1	5897
	11th to 20th	Day	41% 7% 12% 26% 13% 1	5995
	21st to end	Day	39% 6% 11% 24% 17% 2	6949
June	1st to 10th	Day	35% 9% 12% 24% 18% 3	2800
	11th to 20th	Day	35% 7% 12% 25% 20% 3	2800
	21st to end	Day	39% 8% 16% 19% 16% 3	2800
July	1st to 10th	Day	40% 7% 12% 24% 15% 2	6291
	11th to 20th	Day	35% 7% 15% 27% 15% 1	6285
	21st to end	Day	40% 7% 14% 22% 15% 2	6728
August	1st to 10th	Day	33% 6% 15% 28% 16% 1	4353
	11th to 20th	Day	35% 7% 11% 29% 17% 1	3958
	21st to end	Day	31% 7% 13% 26% 20% 4	4311
September	1st to 10th	Day	33% 7% 12% 26% 17% 4	2400
	11th to 20th	Day	31% 6% 11% 26% 22% 3	2237
	21st to end	Day	36% 6% 11% 26% 20% 2	2200
October	1st to 10th	Day	26% 4 7% 32% 28% 2	3590
	11th to 20th	Day	36% 6% 12% 22% 24% 1	3167
	21st to end	Day	45% 4 9% 26% 14% 2	3180
November	1st to 10th	Day	38% 5% 14% 24% 16% 2	1852
	11th to 20th	Day	50% 5% 11% 21% 12% 1	1890
	21st to end	Day	53% 5% 9% 22% 10%	1890
December	1st to 10th	Day	46% 4 15% 26% 9%	2700
	11th to 20th	Day	61% 5% 12% 16% 5%	3061
	21st to end	Day	78% 4 7% 8% 2	3982
January	1st to 10th	Night	60% 6% 8% 16% 9%	6348
	11th to 20th	Night	67% 4 9% 8% 10% 2	6360
	21st to end	Night	59% 4 10% 17% 10% 1	6929
February	1st to 10th	Night	57% 4 11% 17% 10% 2	2493
	11th to 20th	Night	50% 5% 11% 20% 13% 1	2339
	21st to end	Night	52% 5% 11% 19% 11% 3	1980
March	1st to 10th	Night	48% 5% 9% 25% 11% 2	5373
	11th to 20th	Night	38% 4 13% 28% 15% 2	5302
	21st to end	Night	55% 6% 9% 20% 9%	5018
April	1st to 10th	Night	45% 5% 12% 22% 14% 1	2000
	11th to 20th	Night	46% 5% 9% 20% 16% 3	1975
	21st to end	Night	47% 7% 10% 21% 13% 2	1865
May	1st to 10th	Night	51% 6% 10% 16% 14% 4	4060
	11th to 20th	Night	39% 8% 13% 25% 13% 2	3906
	21st to end	Night	44% 7% 10% 18% 18% 3	3950
June	1st to 10th	Night	32% 7% 12% 27% 20% 3	1600
	11th to 20th	Night	34% 7% 11% 23% 22% 3	1600
	21st to end	Night	38% 8% 14% 22% 15% 3	1600
July	1st to 10th	Night	37% 5% 12% 28% 14% 4	3580
	11th to 20th	Night	32% 6% 15% 23% 22% 2	3572
	21st to end	Night	37% 7% 15% 23% 15% 4	3832
August	1st to 10th	Night	31% 8% 15% 28% 16% 1	2774
	11th to 20th	Night	30% 6% 14% 28% 20% 1	3154
	21st to end	Night	30% 6% 10% 31% 19% 3	3586
September	1st to 10th	Night	31% 7% 11% 25% 21% 5%	2000
	11th to 20th	Night	26% 6% 9% 28% 27% 4	2141
	21st to end	Night	37% 5% 10% 27% 19% 3	2200
October	1st to 10th	Night	22% 4 8% 33% 31% 2	3590
	11th to 20th	Night	35% 5% 8% 22% 28% 2	3955
	21st to end	Night	39% 4 9% 25% 21% 3	4610
November	1st to 10th	Night	40% 5% 10% 25% 18% 3	2666
	11th to 20th	Night	46% 6% 12% 21% 13% 2	2730
	21st to end	Night	52% 5% 11% 22% 10%	2730
December	1st to 10th	Night	44% 4 13% 26% 11% 2	4704
	11th to 20th	Night	57% 4 13% 15% 10% 1	5300
	21st to end	Night	72% 5% 9% 9% 5%	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	20% 14% 35% 24% 6% 1	300
	11th to 20th	Day	22% 17% 41% 14% 4 1	300
	21st to end	Day	20% 21% 34% 19% 6%	330
February	1st to 10th	Day	22% 21% 37% 17% 3	300
	11th to 20th	Day	25% 17% 37% 17% 4 1	300
	21st to end	Day	22% 22% 43% 10% 3	249
March	1st to 10th	Day	23% 20% 38% 18% 2	300
	11th to 20th	Day	22% 18% 35% 18% 6%	359
	21st to end	Day	27% 19% 30% 19% 5%	550
April	1st to 10th	Day	24% 15% 32% 21% 6% 1	500
	11th to 20th	Day	23% 18% 30% 16% 11% 2	492
	21st to end	Day	24% 13% 37% 16% 8% 2	500
May	1st to 10th	Day	23% 15% 31% 19% 10% 2	503
	11th to 20th	Day	19% 9% 32% 21% 15% 3	579
	21st to end	Day	14% 10% 31% 26% 13% 6%	789
June	1st to 10th	Day	11% 10% 31% 29% 14% 5%	730
	11th to 20th	Day	12% 6% 32% 30% 16% 4	730
	21st to end	Day	12% 8% 33% 30% 12% 5%	730
July	1st to 10th	Day	8% 6% 22% 32% 19% 13%	721
	11th to 20th	Day	9% 5% 24% 31% 20% 10%	718
	21st to end	Day	9% 4 26% 32% 22% 7%	794
August	1st to 10th	Day	7% 4 18% 32% 27% 12%	609
	11th to 20th	Day	9% 5% 21% 29% 24% 11%	519
	21st to end	Day	8% 3 18% 35% 26% 11%	583
September	1st to 10th	Day	10% 7% 22% 31% 21% 10%	530
	11th to 20th	Day	10% 5% 14% 29% 28% 14%	530
	21st to end	Day	13% 9% 24% 28% 18% 8%	530
October	1st to 10th	Day	13% 7% 29% 30% 17% 4	530
	11th to 20th	Day	17% 22% 26% 26% 8%	335
	21st to end	Day	29% 13% 36% 17% 4 1	363
November	1st to 10th	Day	15% 15% 38% 22% 9% 2	330
	11th to 20th	Day	22% 15% 38% 17% 7% 1	330
	21st to end	Day	26% 14% 38% 19% 4	330
December	1st to 10th	Day	17% 20% 40% 17% 6%	330
	11th to 20th	Day	19% 20% 38% 17% 6%	321
	21st to end	Day	28% 21% 34% 15% 2	330
January	1st to 10th	Night	21% 16% 37% 23% 4	1000
	11th to 20th	Night	21% 16% 39% 20% 4 1	1000
	21st to end	Night	22% 14% 37% 24% 4	1100
February	1st to 10th	Night	24% 12% 40% 21% 3	893
	11th to 20th	Night	20% 15% 36% 25% 3	783
	21st to end	Night	24% 14% 39% 20% 2	660
March	1st to 10th	Night	22% 15% 36% 23% 5%	800
	11th to 20th	Night	18% 13% 40% 24% 6%	800
	21st to end	Night	23% 13% 35% 22% 7%	690
April	1st to 10th	Night	18% 14% 39% 23% 6% 1	600
	11th to 20th	Night	20% 13% 35% 25% 7% 1	593
	21st to end	Night	21% 9% 34% 28% 7% 1	600
May	1st to 10th	Night	19% 8% 34% 28% 11% 1	600
	11th to 20th	Night	18% 5% 28% 35% 13% 1	591
	21st to end	Night	12% 4 27% 38% 18% 1	650
June	1st to 10th	Night	10% 4 24% 46% 16%	600
	11th to 20th	Night	10% 3 31% 40% 14% 1	600
	21st to end	Night	10% 5% 28% 39% 18% 1	600
July	1st to 10th	Night	8% 2 18% 43% 25% 4	585
	11th to 20th	Night	7% 3 19% 41% 27% 4	582
	21st to end	Night	5% 2 16% 48% 27% 1	657
August	1st to 10th	Night	6% 2 12% 47% 30% 4	597
	11th to 20th	Night	7% 1 15% 43% 30% 4	594
	21st to end	Night	7% 3 16% 41% 30% 3	660
September	1st to 10th	Night	11% 4 19% 38% 25% 4	600
	11th to 20th	Night	7% 4 17% 39% 30% 3	741
	21st to end	Night	11% 7% 23% 33% 24% 3	800
October	1st to 10th	Night	12% 6% 25% 38% 18% 1	800
	11th to 20th	Night	19% 14% 30% 28% 9%	800
	21st to end	Night	23% 14% 32% 24% 7%	880
November	1st to 10th	Night	17% 12% 36% 25% 9% 1	820
	11th to 20th	Night	18% 16% 37% 23% 5%	840
	21st to end	Night	23% 15% 33% 23% 6%	840
December	1st to 10th	Night	23% 14% 37% 22% 4	1034
	11th to 20th	Night	23% 12% 37% 24% 4	1036
	21st to end	Night	29% 14% 34% 21% 2	1100

Page generated at 2025-12-15 00:13:53. Version ac07

Copyright © 2025 Attilla Danko.