Lake Harris Campground
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lake Harris Campground clear sky chart from 2005-11-06 to 2025-02-06.

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	17% 12% 4 10% 6% 5% 5% 4 5% 6% 27%	108428
	Night	16% 13% 5% 12% 6% 5% 4 3 5% 5% 25%	109803
Transparency	Day	54% 7% 12% 18% 9% 1	111942
	Night	57% 7% 12% 16% 8% 1	114453
Seeing	Day	26% 18% 27% 18% 9% 3	14897
	Night	24% 17% 25% 23% 9% 1	24078

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% 20% 13% 5% 4 2 4 4 15%	3597
	11th to 20th	Day	10% 14% 7% 22% 14% 5% 4 2 3 3 15%	3570
	21st to end	Day	11% 15% 9% 15% 7% 6% 7% 4 4 5% 17%	4034
February	1st to 10th	Day	13% 17% 6% 12% 9% 5% 4 5% 5% 5% 19%	1755
	11th to 20th	Day	11% 13% 8% 16% 9% 5% 4 4 5% 4 20%	1774
	21st to end	Day	16% 17% 5% 13% 6% 5% 4 3 4 6% 21%	1570
March	1st to 10th	Day	20% 18% 6% 12% 6% 4 3 3 4 4 20%	3116
	11th to 20th	Day	11% 18% 9% 15% 6% 4 5% 3 4 4 22%	3320
	21st to end	Day	15% 13% 4 10% 7% 4 3 2 3 4 33%	4133
April	1st to 10th	Day	20% 15% 5% 8% 5% 4 4 3 4 5% 28%	2280
	11th to 20th	Day	18% 14% 4 8% 4 5% 4 3 4 5% 32%	2254
	21st to end	Day	21% 13% 4 10% 4 4 5% 3 4 5% 27%	2380
May	1st to 10th	Day	24% 12% 3 7% 5% 4 4 3 5% 6% 26%	4316
	11th to 20th	Day	19% 10% 3 8% 5% 5% 6% 4 5% 7% 28%	4398
	21st to end	Day	15% 8% 3 7% 5% 5% 5% 4 6% 8% 34%	4837
June	1st to 10th	Day	20% 8% 3 8% 7% 6% 5% 4 6% 7% 26%	2660
	11th to 20th	Day	18% 8% 3 7% 6% 5% 5% 6% 7% 8% 29%	2660
	21st to end	Day	21% 9% 3 8% 5% 5% 5% 4 6% 7% 26%	2660
July	1st to 10th	Day	14% 6% 3 7% 5% 5% 6% 5% 7% 10% 33%	4440
	11th to 20th	Day	13% 8% 3 7% 5% 5% 6% 5% 8% 10% 31%	4440
	21st to end	Day	15% 7% 3 7% 6% 5% 6% 5% 7% 8% 32%	4814
August	1st to 10th	Day	17% 8% 3 7% 5% 5% 5% 5% 7% 8% 30%	4423
	11th to 20th	Day	17% 8% 3 8% 5% 5% 6% 5% 8% 9% 27%	3831
	21st to end	Day	16% 6% 3 6% 5% 5% 5% 5% 7% 9% 33%	4180
September	1st to 10th	Day	17% 6% 2 6% 5% 5% 4 4 6% 7% 38%	2280
	11th to 20th	Day	16% 6% 2 5% 4 3 4 4 5% 7% 43%	2211
	21st to end	Day	20% 7% 2 6% 3 4 4 4 6% 7% 35%	2090
October	1st to 10th	Day	25% 12% 3 6% 5% 5% 3 3 4 5% 29%	1950
	11th to 20th	Day	19% 14% 3 7% 3 5% 4 4 6% 6% 29%	1900
	21st to end	Day	24% 15% 5% 9% 4 5% 4 2 5% 5% 22%	1884
November	1st to 10th	Day	15% 14% 4 9% 6% 5% 5% 3 5% 5% 28%	1761
	11th to 20th	Day	16% 15% 7% 9% 6% 4 4 4 4 5% 27%	1764
	21st to end	Day	18% 17% 7% 10% 7% 4 5% 3 4 5% 20%	1600
December	1st to 10th	Day	17% 25% 8% 18% 8% 4 2 2 2 3 10%	2600
	11th to 20th	Day	17% 21% 6% 15% 5% 4 3 3 3 5% 17%	2986
	21st to end	Day	17% 17% 7% 13% 5% 3 3 3 4 5% 22%	3960
January	1st to 10th	Night	11% 15% 8% 22% 9% 6% 4 3 4 4 14%	6349
	11th to 20th	Night	8% 16% 9% 24% 14% 6% 5% 3 4 3 9%	6315
	21st to end	Night	11% 14% 7% 18% 8% 7% 8% 4 4 4 13%	6908
February	1st to 10th	Night	13% 16% 5% 15% 10% 7% 6% 4 5% 4 17%	2536
	11th to 20th	Night	11% 12% 5% 15% 10% 7% 5% 4 5% 6% 19%	2291
	21st to end	Night	13% 14% 6% 13% 7% 6% 5% 4 5% 6% 21%	1884
March	1st to 10th	Night	20% 16% 4 8% 8% 5% 5% 3 4 5% 23%	3724
	11th to 20th	Night	13% 16% 8% 13% 5% 4 3 3 3 5% 27%	3621
	21st to end	Night	15% 13% 5% 10% 6% 5% 3 3 3 4 31%	3498
April	1st to 10th	Night	20% 11% 5% 9% 6% 4 5% 4 4 5% 27%	1900
	11th to 20th	Night	19% 13% 4 8% 5% 4 4 3 5% 5% 29%	1875
	21st to end	Night	19% 10% 5% 9% 5% 4 4 3 5% 6% 31%	1800
May	1st to 10th	Night	23% 12% 3 9% 4 5% 4 3 5% 6% 26%	2654
	11th to 20th	Night	23% 13% 3 8% 4 4 4 3 4 5% 30%	2495
	21st to end	Night	14% 8% 3 7% 4 4 5% 4 6% 7% 36%	2738
June	1st to 10th	Night	20% 8% 2 7% 5% 4 4 4 5% 8% 34%	1520
	11th to 20th	Night	18% 7% 2 6% 5% 4 4 4 6% 8% 37%	1520
	21st to end	Night	19% 8% 2 6% 5% 5% 5% 4 7% 7% 33%	1520
July	1st to 10th	Night	13% 6% 3 7% 6% 6% 6% 4 6% 7% 37%	2520
	11th to 20th	Night	14% 8% 3 7% 4 4 5% 3 5% 8% 39%	2520
	21st to end	Night	11% 8% 3 6% 5% 4 4 4 6% 9% 39%	2739
August	1st to 10th	Night	19% 9% 4 8% 4 4 4 3 4 6% 37%	2506
	11th to 20th	Night	18% 9% 3 7% 4 4 4 3 6% 7% 35%	2961
	21st to end	Night	12% 6% 2 6% 4 5% 5% 5% 7% 9% 38%	3476
September	1st to 10th	Night	14% 8% 3 6% 4 3 4 3 4 7% 43%	1900
	11th to 20th	Night	14% 6% 2 6% 4 4 3 3 5% 7% 46%	1967
	21st to end	Night	18% 8% 2 5% 4 4 4 3 6% 7% 39%	2090
October	1st to 10th	Night	22% 11% 4 7% 5% 4 4 3 5% 6% 29%	2228
	11th to 20th	Night	18% 13% 3 8% 5% 5% 4 4 5% 6% 30%	2280
	21st to end	Night	22% 15% 5% 9% 6% 5% 5% 4 4 5% 21%	2712
November	1st to 10th	Night	14% 14% 5% 11% 5% 4 5% 4 6% 6% 27%	2537
	11th to 20th	Night	17% 14% 5% 10% 6% 4 5% 4 4 5% 26%	2635
	21st to end	Night	17% 16% 6% 13% 6% 5% 4 4 6% 5% 19%	2800
December	1st to 10th	Night	16% 20% 9% 22% 7% 4 4 3 3 3 9%	4580
	11th to 20th	Night	22% 18% 6% 12% 6% 4 4 3 3 3 19%	5208
	21st to end	Night	19% 18% 5% 14% 5% 4 3 3 4 5% 19%	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	70% 5% 9% 12% 4	3598
	11th to 20th	Day	74% 4 6% 6% 7% 2	3600
	21st to end	Day	66% 6% 10% 10% 6% 2	4034
February	1st to 10th	Day	65% 5% 10% 15% 4 2	1755
	11th to 20th	Day	65% 5% 9% 12% 8% 1	1783
	21st to end	Day	63% 5% 10% 11% 9% 1	1570
March	1st to 10th	Day	65% 7% 8% 9% 9% 1	3119
	11th to 20th	Day	65% 5% 10% 11% 8% 2	3320
	21st to end	Day	53% 6% 7% 15% 17% 2	4133
April	1st to 10th	Day	58% 3 10% 16% 11% 2	2280
	11th to 20th	Day	54% 5% 8% 19% 13% 1	2254
	21st to end	Day	59% 5% 9% 13% 11% 3	2380
May	1st to 10th	Day	56% 8% 9% 19% 8% 1	4330
	11th to 20th	Day	53% 9% 12% 18% 7% 1	4402
	21st to end	Day	44% 8% 13% 24% 10% 1	4837
June	1st to 10th	Day	55% 8% 12% 15% 9% 1	2660
	11th to 20th	Day	50% 8% 12% 20% 10% 1	2660
	21st to end	Day	55% 8% 12% 17% 8% 1	2660
July	1st to 10th	Day	41% 9% 16% 23% 10%	4370
	11th to 20th	Day	41% 10% 17% 26% 6%	4365
	21st to end	Day	45% 9% 13% 26% 7%	4661
August	1st to 10th	Day	47% 9% 15% 18% 10%	4409
	11th to 20th	Day	47% 11% 18% 20% 5%	3870
	21st to end	Day	42% 8% 17% 24% 9% 1	4180
September	1st to 10th	Day	43% 6% 11% 29% 11% 1	2280
	11th to 20th	Day	39% 5% 12% 27% 16% 1	2211
	21st to end	Day	46% 6% 13% 21% 12% 1	2090
October	1st to 10th	Day	50% 6% 11% 22% 10%	3236
	11th to 20th	Day	47% 6% 14% 18% 15% 1	3140
	21st to end	Day	47% 6% 15% 25% 6% 1	3084
November	1st to 10th	Day	55% 7% 12% 17% 9%	1761
	11th to 20th	Day	57% 6% 10% 15% 10% 3	1764
	21st to end	Day	65% 5% 12% 12% 5% 1	1600
December	1st to 10th	Day	80% 3 7% 8% 2	2600
	11th to 20th	Day	68% 5% 9% 13% 4	2986
	21st to end	Day	63% 5% 7% 10% 13% 1	3960
January	1st to 10th	Night	71% 6% 10% 9% 4	6349
	11th to 20th	Night	77% 6% 7% 6% 4 1	6360
	21st to end	Night	69% 6% 9% 9% 6% 1	6908
February	1st to 10th	Night	67% 5% 11% 11% 5% 1	2536
	11th to 20th	Night	62% 5% 11% 14% 7% 1	2293
	21st to end	Night	59% 6% 13% 13% 8% 1	1884
March	1st to 10th	Night	58% 8% 11% 12% 9% 2	3734
	11th to 20th	Night	59% 5% 13% 14% 8% 1	3622
	21st to end	Night	55% 4 8% 16% 14% 3	3498
April	1st to 10th	Night	57% 4 11% 18% 9% 2	1900
	11th to 20th	Night	53% 6% 12% 17% 11%	1875
	21st to end	Night	53% 6% 10% 18% 11% 3	1800
May	1st to 10th	Night	56% 8% 10% 16% 9% 1	2660
	11th to 20th	Night	53% 9% 12% 17% 8% 1	2496
	21st to end	Night	43% 9% 14% 20% 14% 1	2739
June	1st to 10th	Night	48% 7% 14% 22% 8% 1	1520
	11th to 20th	Night	44% 7% 16% 20% 12% 1	1520
	21st to end	Night	47% 8% 15% 21% 8%	1520
July	1st to 10th	Night	43% 9% 16% 20% 12% 1	2480
	11th to 20th	Night	39% 10% 15% 28% 7%	2472
	21st to end	Night	39% 9% 17% 26% 8% 1	2651
August	1st to 10th	Night	47% 7% 16% 21% 8%	2496
	11th to 20th	Night	45% 7% 19% 22% 6%	2988
	21st to end	Night	35% 10% 19% 25% 9% 1	3476
September	1st to 10th	Night	39% 8% 15% 27% 10% 1	1900
	11th to 20th	Night	36% 7% 13% 31% 12% 1	1967
	21st to end	Night	43% 6% 14% 24% 12% 2	2090
October	1st to 10th	Night	51% 8% 12% 20% 9%	3722
	11th to 20th	Night	46% 7% 13% 19% 10% 4	3779
	21st to end	Night	52% 6% 14% 21% 5% 1	4462
November	1st to 10th	Night	54% 7% 12% 15% 9% 2	2537
	11th to 20th	Night	57% 5% 11% 15% 9% 3	2635
	21st to end	Night	62% 6% 13% 13% 5% 1	2800
December	1st to 10th	Night	78% 6% 8% 7% 2	4580
	11th to 20th	Night	69% 4 8% 11% 7%	5208
	21st to end	Night	66% 5% 8% 8% 9% 3	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	27% 24% 34% 10% 6%	200
	11th to 20th	Day	29% 23% 35% 10% 3 1	200
	21st to end	Day	24% 31% 30% 11% 3 1	237
February	1st to 10th	Day	36% 30% 27% 6% 1	285
	11th to 20th	Day	35% 24% 30% 9% 1	382
	21st to end	Day	35% 23% 26% 14% 2	382
March	1st to 10th	Day	29% 21% 31% 15% 4	460
	11th to 20th	Day	31% 24% 28% 13% 4 1	460
	21st to end	Day	32% 25% 23% 12% 6% 2	506
April	1st to 10th	Day	36% 19% 25% 13% 6% 1	460
	11th to 20th	Day	36% 20% 21% 15% 6% 2	452
	21st to end	Day	33% 18% 28% 11% 7% 3	460
May	1st to 10th	Day	34% 17% 27% 11% 8% 4	463
	11th to 20th	Day	23% 19% 26% 21% 9% 2	487
	21st to end	Day	21% 17% 33% 17% 10% 3	529
June	1st to 10th	Day	26% 16% 29% 20% 8% 1	490
	11th to 20th	Day	21% 16% 30% 21% 11% 2	490
	21st to end	Day	25% 19% 28% 19% 8% 2	490
July	1st to 10th	Day	18% 10% 29% 27% 13% 3	485
	11th to 20th	Day	13% 12% 36% 26% 12% 2	484
	21st to end	Day	16% 11% 35% 26% 10% 2	532
August	1st to 10th	Day	16% 12% 24% 26% 15% 7%	486
	11th to 20th	Day	19% 11% 27% 21% 14% 8%	479
	21st to end	Day	14% 16% 26% 23% 14% 7%	539
September	1st to 10th	Day	18% 10% 28% 20% 15% 9%	490
	11th to 20th	Day	16% 11% 24% 19% 19% 12%	490
	21st to end	Day	20% 12% 28% 20% 14% 5%	490
October	1st to 10th	Day	31% 13% 20% 19% 13% 4	490
	11th to 20th	Day	26% 20% 24% 20% 9% 2	490
	21st to end	Day	33% 17% 24% 20% 6%	430
November	1st to 10th	Day	30% 19% 21% 21% 9%	395
	11th to 20th	Day	30% 23% 21% 19% 6% 1	364
	21st to end	Day	35% 23% 29% 13% 2	200
December	1st to 10th	Day	32% 21% 30% 15% 3 1	200
	11th to 20th	Day	38% 23% 25% 11% 3 1	200
	21st to end	Day	32% 21% 28% 14% 4 1	220
January	1st to 10th	Night	27% 24% 31% 16% 2	800
	11th to 20th	Night	28% 24% 29% 16% 3	800
	21st to end	Night	18% 25% 31% 21% 5%	880
February	1st to 10th	Night	26% 25% 30% 17% 2	781
	11th to 20th	Night	25% 27% 31% 16% 2	743
	21st to end	Night	26% 22% 30% 19% 3	628
March	1st to 10th	Night	27% 20% 30% 20% 2	760
	11th to 20th	Night	27% 23% 26% 19% 4	760
	21st to end	Night	27% 20% 26% 20% 7% 1	836
April	1st to 10th	Night	27% 19% 29% 20% 4	760
	11th to 20th	Night	29% 18% 25% 20% 7% 1	751
	21st to end	Night	28% 18% 24% 22% 8%	660
May	1st to 10th	Night	28% 15% 21% 24% 11%	468
	11th to 20th	Night	18% 16% 23% 34% 8% 1	374
	21st to end	Night	15% 9% 28% 31% 15% 1	411
June	1st to 10th	Night	22% 11% 23% 31% 13% 1	380
	11th to 20th	Night	20% 7% 22% 37% 14%	380
	21st to end	Night	19% 10% 24% 34% 11% 1	380
July	1st to 10th	Night	14% 6% 24% 36% 19% 1	370
	11th to 20th	Night	15% 7% 22% 37% 17% 2	368
	21st to end	Night	11% 9% 20% 44% 15% 1	416
August	1st to 10th	Night	18% 5% 18% 40% 19% 1	378
	11th to 20th	Night	17% 6% 20% 32% 21% 4	662
	21st to end	Night	16% 8% 20% 33% 22% 1	836
September	1st to 10th	Night	16% 9% 23% 32% 17% 3	760
	11th to 20th	Night	14% 9% 21% 28% 24% 4	760
	21st to end	Night	23% 11% 20% 24% 19% 3	760
October	1st to 10th	Night	26% 15% 22% 21% 15% 2	760
	11th to 20th	Night	25% 17% 19% 28% 10% 1	760
	21st to end	Night	31% 19% 25% 21% 6%	836
November	1st to 10th	Night	24% 18% 26% 24% 7% 1	780
	11th to 20th	Night	30% 18% 23% 20% 8% 2	800
	21st to end	Night	29% 21% 26% 18% 6% 1	800
December	1st to 10th	Night	30% 25% 26% 15% 4	800
	11th to 20th	Night	31% 23% 22% 19% 4 1	800
	21st to end	Night	32% 23% 23% 18% 4	880

Page generated at 2025-02-03 03:05:56. Version ac07

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