This page made possible by the sponsorship of:

Gardner Camp Youth Astronomy Club

.

Gardner Camp
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Gardner Camp clear sky chart from 2005-11-06 to 2024-11-05.

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	12% 7% 3 6% 4 4 4 4 6% 7% 41%	101313
	Night	13% 8% 3 7% 4 4 4 3 5% 6% 42%	97781
Transparency	Day	40% 6% 12% 24% 16% 2	104946
	Night	40% 5% 11% 23% 17% 3	102289
Seeing	Day	14% 10% 28% 27% 16% 5%	15706
	Night	16% 10% 30% 31% 13% 1	25521

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% 11% 6% 13% 6% 4 4 3 5% 7% 28%	2527
	11th to 20th	Day	12% 10% 4 10% 7% 7% 5% 4 5% 5% 31%	2736
	21st to end	Day	17% 19% 9% 9% 4 4 3 3 3 4 25%	3135
February	1st to 10th	Day	15% 11% 5% 9% 5% 4 4 3 5% 6% 33%	1710
	11th to 20th	Day	13% 11% 3 6% 5% 5% 5% 4 6% 6% 36%	1760
	21st to end	Day	15% 11% 3 8% 5% 4 4 3 4 6% 37%	1570
March	1st to 10th	Day	18% 11% 3 6% 4 3 3 2 3 5% 41%	3247
	11th to 20th	Day	10% 7% 2 5% 4 4 4 3 5% 7% 48%	3480
	21st to end	Day	18% 12% 4 7% 5% 5% 4 3 5% 6% 32%	3963
April	1st to 10th	Day	14% 8% 3 7% 5% 3 4 4 5% 6% 40%	2280
	11th to 20th	Day	16% 8% 3 7% 4 4 4 3 5% 6% 40%	2254
	21st to end	Day	20% 6% 3 7% 4 4 4 4 5% 7% 35%	2280
May	1st to 10th	Day	13% 8% 3 7% 5% 5% 6% 4 7% 9% 34%	3967
	11th to 20th	Day	17% 7% 3 6% 5% 4 4 3 5% 8% 38%	4399
	21st to end	Day	11% 6% 2 6% 5% 4 4 4 5% 7% 46%	4824
June	1st to 10th	Day	6% 4 2 5% 4 5% 5% 5% 7% 10% 47%	2660
	11th to 20th	Day	8% 4 2 5% 4 4 5% 4 7% 9% 47%	2660
	21st to end	Day	8% 5% 3 6% 5% 5% 5% 4 6% 9% 45%	2660
July	1st to 10th	Day	13% 5% 2 5% 4 4 5% 5% 7% 9% 39%	4440
	11th to 20th	Day	5% 4 2 5% 4 4 5% 4 7% 10% 49%	4440
	21st to end	Day	8% 5% 2 5% 5% 5% 6% 5% 8% 10% 41%	4545
August	1st to 10th	Day	5% 4 2 5% 4 4 5% 5% 7% 9% 49%	4104
	11th to 20th	Day	13% 5% 2 6% 4 4 5% 4 7% 9% 42%	3829
	21st to end	Day	6% 3 2 5% 3 4 5% 5% 7% 10% 51%	4180
September	1st to 10th	Day	11% 5% 1 5% 3 4 3 4 6% 7% 51%	2280
	11th to 20th	Day	10% 5% 2 6% 3 3 3 3 5% 7% 53%	2280
	21st to end	Day	8% 4 2 5% 4 5% 4 4 6% 7% 51%	2030
October	1st to 10th	Day	12% 5% 2 5% 3 3 3 3 4 7% 53%	1900
	11th to 20th	Day	16% 6% 2 6% 3 3 3 3 5% 6% 48%	1900
	21st to end	Day	19% 7% 3 6% 4 3 3 3 4 6% 43%	2090
November	1st to 10th	Day	11% 7% 2 5% 3 3 3 3 5% 6% 52%	1713
	11th to 20th	Day	16% 7% 3 7% 3 3 4 3 5% 6% 44%	1710
	21st to end	Day	16% 11% 3 7% 4 4 3 4 4 6% 38%	1539
December	1st to 10th	Day	13% 11% 3 7% 6% 4 4 3 4 7% 39%	1520
	11th to 20th	Day	14% 10% 4 7% 4 5% 4 4 5% 6% 37%	1918
	21st to end	Day	21% 15% 6% 11% 4 4 4 3 4 5% 22%	2783
January	1st to 10th	Night	13% 13% 6% 11% 5% 4 4 3 4 4 32%	4428
	11th to 20th	Night	13% 16% 6% 10% 4 5% 7% 4 5% 4 26%	4216
	21st to end	Night	20% 19% 6% 9% 4 3 3 3 4 5% 24%	4532
February	1st to 10th	Night	15% 13% 4 7% 5% 4 3 4 5% 6% 33%	2470
	11th to 20th	Night	14% 8% 3 7% 6% 4 4 4 5% 6% 39%	2305
	21st to end	Night	16% 9% 4 7% 4 3 3 3 4 5% 41%	1884
March	1st to 10th	Night	19% 11% 3 5% 4 2 3 3 4 6% 41%	3623
	11th to 20th	Night	14% 7% 3 5% 3 3 4 3 4 5% 50%	3480
	21st to end	Night	21% 10% 3 8% 6% 5% 4 4 5% 6% 29%	3668
April	1st to 10th	Night	13% 7% 3 6% 5% 4 4 3 5% 6% 45%	1900
	11th to 20th	Night	14% 7% 3 5% 4 3 4 4 5% 7% 44%	1875
	21st to end	Night	18% 7% 2 7% 4 4 4 3 4 6% 41%	1900
May	1st to 10th	Night	16% 8% 3 6% 5% 4 5% 3 6% 8% 36%	2925
	11th to 20th	Night	13% 7% 3 7% 5% 4 4 3 5% 7% 42%	2506
	21st to end	Night	8% 5% 2 5% 4 3 4 4 5% 9% 49%	2743
June	1st to 10th	Night	7% 5% 2 4 3 3 4 4 6% 9% 52%	1520
	11th to 20th	Night	8% 4 2 7% 4 4 4 4 6% 8% 50%	1520
	21st to end	Night	7% 4 1 6% 3 4 5% 5% 6% 10% 50%	1520
July	1st to 10th	Night	13% 6% 2 7% 4 4 4 3 7% 9% 42%	2530
	11th to 20th	Night	4 3 1 4 3 3 4 4 6% 8% 59%	2530
	21st to end	Night	9% 5% 2 5% 4 4 6% 4 7% 10% 44%	3001
August	1st to 10th	Night	4 2 1 4 4 3 4 3 6% 10% 59%	2836
	11th to 20th	Night	10% 4 2 5% 4 4 4 3 5% 7% 52%	3000
	21st to end	Night	4 3 1 5% 3 4 4 5% 7% 10% 54%	3476
September	1st to 10th	Night	10% 5% 1 4 3 3 4 3 5% 6% 56%	1900
	11th to 20th	Night	8% 5% 2 6% 3 3 5% 3 6% 7% 53%	1900
	21st to end	Night	7% 4 2 6% 4 4 4 3 4 7% 55%	2127
October	1st to 10th	Night	9% 4 1 5% 3 3 3 3 5% 6% 57%	2280
	11th to 20th	Night	14% 5% 2 5% 3 3 3 3 4 6% 53%	2280
	21st to end	Night	17% 8% 2 5% 3 4 4 3 5% 6% 44%	2508
November	1st to 10th	Night	11% 5% 2 5% 3 3 3 3 5% 7% 54%	2465
	11th to 20th	Night	12% 7% 3 6% 4 4 3 2 4 6% 48%	2470
	21st to end	Night	17% 9% 3 5% 3 3 4 3 5% 5% 42%	2640
December	1st to 10th	Night	14% 11% 3 7% 5% 4 5% 5% 5% 6% 35%	2660
	11th to 20th	Night	15% 10% 3 6% 4 4 3 3 4 6% 41%	3279
	21st to end	Night	21% 18% 7% 11% 5% 4 3 2 3 4 21%	4884

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	53% 6% 11% 21% 8%	2528
	11th to 20th	Day	55% 4 14% 18% 9%	2736
	21st to end	Day	63% 5% 9% 14% 9% 1	3135
February	1st to 10th	Day	52% 5% 12% 19% 10% 2	1710
	11th to 20th	Day	47% 6% 12% 20% 13% 1	1769
	21st to end	Day	49% 4 11% 23% 11% 3	1570
March	1st to 10th	Day	47% 4 8% 22% 16% 2	3247
	11th to 20th	Day	35% 6% 13% 26% 18% 3	3480
	21st to end	Day	52% 7% 17% 18% 5% 1	3963
April	1st to 10th	Day	44% 5% 12% 25% 14% 1	2280
	11th to 20th	Day	44% 5% 9% 25% 14% 2	2254
	21st to end	Day	46% 6% 13% 19% 14% 1	2280
May	1st to 10th	Day	43% 9% 14% 23% 10% 1	4002
	11th to 20th	Day	45% 7% 11% 27% 9% 1	4403
	21st to end	Day	35% 7% 10% 23% 23% 1	4837
June	1st to 10th	Day	30% 8% 16% 28% 15% 3	2660
	11th to 20th	Day	32% 8% 12% 24% 21% 3	2660
	21st to end	Day	35% 7% 15% 24% 16% 3	2660
July	1st to 10th	Day	39% 7% 13% 26% 13% 2	4371
	11th to 20th	Day	29% 7% 15% 29% 18% 2	4365
	21st to end	Day	35% 7% 20% 26% 11% 1	4402
August	1st to 10th	Day	29% 8% 15% 35% 12% 1	4090
	11th to 20th	Day	38% 6% 13% 27% 14% 1	3867
	21st to end	Day	27% 7% 18% 31% 14% 4	4179
September	1st to 10th	Day	31% 6% 11% 25% 21% 6%	2280
	11th to 20th	Day	31% 4 10% 30% 21% 4	2280
	21st to end	Day	31% 6% 10% 28% 23% 2	2030
October	1st to 10th	Day	21% 3 7% 17% 46% 6%	3160
	11th to 20th	Day	25% 3 7% 21% 37% 7%	3140
	21st to end	Day	40% 3 7% 24% 24% 2	3428
November	1st to 10th	Day	33% 4 14% 25% 20% 4	1713
	11th to 20th	Day	41% 4 10% 25% 18% 3	1710
	21st to end	Day	48% 6% 10% 25% 12%	1539
December	1st to 10th	Day	47% 4 14% 22% 12% 1	1520
	11th to 20th	Day	45% 7% 12% 24% 10% 2	1915
	21st to end	Day	63% 6% 10% 14% 6% 1	2783
January	1st to 10th	Night	54% 5% 10% 22% 8%	4428
	11th to 20th	Night	60% 4 9% 17% 9%	4216
	21st to end	Night	63% 5% 10% 17% 6% 1	4532
February	1st to 10th	Night	52% 5% 12% 19% 11% 2	2470
	11th to 20th	Night	45% 5% 11% 23% 14% 2	2306
	21st to end	Night	45% 5% 10% 24% 13% 3	1884
March	1st to 10th	Night	45% 5% 9% 24% 15% 1	3623
	11th to 20th	Night	37% 5% 8% 26% 19% 5%	3480
	21st to end	Night	54% 8% 11% 22% 5%	3668
April	1st to 10th	Night	39% 5% 13% 24% 15% 4	1900
	11th to 20th	Night	39% 4 11% 24% 17% 4	1875
	21st to end	Night	45% 6% 10% 21% 16% 2	1900
May	1st to 10th	Night	44% 8% 14% 21% 11% 1	2955
	11th to 20th	Night	41% 7% 13% 26% 12% 1	2507
	21st to end	Night	30% 8% 13% 22% 24% 3	2751
June	1st to 10th	Night	27% 7% 16% 29% 18% 3	1520
	11th to 20th	Night	30% 7% 11% 23% 25% 4	1520
	21st to end	Night	29% 8% 16% 23% 20% 4	1520
July	1st to 10th	Night	40% 6% 12% 28% 12% 3	2490
	11th to 20th	Night	22% 6% 12% 34% 24% 2	2482
	21st to end	Night	32% 7% 19% 25% 15% 1	2906
August	1st to 10th	Night	20% 6% 19% 36% 17% 2	2826
	11th to 20th	Night	32% 5% 13% 28% 21% 1	3028
	21st to end	Night	25% 6% 19% 30% 16% 4	3476
September	1st to 10th	Night	28% 5% 11% 22% 25% 7%	1900
	11th to 20th	Night	30% 6% 10% 24% 26% 4	1900
	21st to end	Night	29% 5% 9% 26% 27% 4	2127
October	1st to 10th	Night	19% 4 7% 21% 45% 5%	3800
	11th to 20th	Night	25% 3 9% 21% 36% 7%	3779
	21st to end	Night	36% 4 8% 23% 25% 4	4120
November	1st to 10th	Night	31% 5% 12% 27% 20% 5%	2465
	11th to 20th	Night	38% 4 10% 26% 20% 3	2470
	21st to end	Night	44% 4 11% 25% 14% 1	2640
December	1st to 10th	Night	48% 5% 14% 22% 10% 1	2660
	11th to 20th	Night	45% 5% 11% 25% 13% 1	3281
	21st to end	Night	68% 5% 8% 12% 6% 1	4884

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	18% 20% 34% 20% 7% 1	270
	11th to 20th	Day	26% 20% 40% 13% 2	270
	21st to end	Day	15% 20% 44% 16% 4	297
February	1st to 10th	Day	24% 17% 40% 16% 3	270
	11th to 20th	Day	22% 23% 34% 16% 5%	270
	21st to end	Day	22% 21% 39% 16% 2	225
March	1st to 10th	Day	19% 24% 44% 12% 1	270
	11th to 20th	Day	26% 18% 34% 19% 3	270
	21st to end	Day	31% 19% 32% 14% 4	382
April	1st to 10th	Day	21% 15% 35% 22% 7% 1	460
	11th to 20th	Day	21% 16% 31% 21% 10% 1	452
	21st to end	Day	20% 15% 36% 23% 5% 1	460
May	1st to 10th	Day	15% 14% 38% 23% 9% 1	540
	11th to 20th	Day	19% 10% 28% 28% 13% 2	675
	21st to end	Day	12% 9% 29% 28% 15% 6%	734
June	1st to 10th	Day	7% 5% 24% 34% 23% 7%	680
	11th to 20th	Day	9% 3 24% 36% 23% 5%	680
	21st to end	Day	8% 7% 30% 34% 17% 4	680
July	1st to 10th	Day	9% 4 17% 32% 25% 13%	671
	11th to 20th	Day	6% 4 20% 37% 26% 7%	668
	21st to end	Day	9% 2 19% 32% 31% 7%	739
August	1st to 10th	Day	7% 4 17% 40% 25% 7%	676
	11th to 20th	Day	8% 4 18% 34% 27% 9%	543
	21st to end	Day	9% 2 14% 34% 32% 10%	539
September	1st to 10th	Day	11% 4 15% 33% 28% 9%	490
	11th to 20th	Day	9% 3 16% 33% 29% 11%	490
	21st to end	Day	9% 10% 21% 32% 19% 8%	416
October	1st to 10th	Day	12% 8% 31% 28% 14% 7%	300
	11th to 20th	Day	15% 21% 34% 20% 10%	300
	21st to end	Day	26% 18% 32% 19% 5%	330
November	1st to 10th	Day	11% 11% 41% 24% 10% 4	282
	11th to 20th	Day	21% 17% 33% 20% 9% 1	270
	21st to end	Day	27% 11% 34% 20% 7%	270
December	1st to 10th	Day	13% 17% 44% 15% 7% 3	270
	11th to 20th	Day	21% 15% 38% 20% 5%	270
	21st to end	Day	26% 22% 36% 13% 3	297
January	1st to 10th	Night	16% 16% 40% 22% 6%	950
	11th to 20th	Night	19% 18% 36% 23% 4	950
	21st to end	Night	20% 13% 39% 25% 2	1045
February	1st to 10th	Night	21% 13% 39% 24% 3	950
	11th to 20th	Night	18% 15% 38% 26% 3	831
	21st to end	Night	23% 16% 36% 22% 2	628
March	1st to 10th	Night	20% 14% 40% 22% 5%	702
	11th to 20th	Night	22% 11% 34% 29% 5%	570
	21st to end	Night	25% 12% 33% 25% 4	627
April	1st to 10th	Night	16% 15% 37% 28% 4	570
	11th to 20th	Night	16% 12% 35% 29% 8% 1	563
	21st to end	Night	21% 9% 35% 29% 6%	570
May	1st to 10th	Night	16% 8% 33% 34% 8% 1	570
	11th to 20th	Night	16% 6% 27% 38% 12% 1	561
	21st to end	Night	11% 4 26% 36% 21% 2	617
June	1st to 10th	Night	8% 4 22% 42% 24% 1	570
	11th to 20th	Night	9% 3 20% 47% 19% 2	570
	21st to end	Night	7% 3 26% 43% 20% 1	570
July	1st to 10th	Night	10% 4 9% 38% 35% 4	555
	11th to 20th	Night	5% 2 16% 45% 28% 3	552
	21st to end	Night	8% 1 13% 44% 32% 1	624
August	1st to 10th	Night	6% 3 10% 46% 33% 2	567
	11th to 20th	Night	8% 2 13% 40% 33% 4	564
	21st to end	Night	4 2 15% 34% 41% 3	627
September	1st to 10th	Night	13% 2 18% 37% 27% 4	570
	11th to 20th	Night	10% 2 17% 38% 27% 6%	570
	21st to end	Night	8% 7% 24% 34% 22% 5%	727
October	1st to 10th	Night	11% 4 28% 32% 23% 3	760
	11th to 20th	Night	16% 10% 32% 30% 10% 1	760
	21st to end	Night	22% 11% 34% 27% 6%	836
November	1st to 10th	Night	14% 9% 36% 31% 9% 1	760
	11th to 20th	Night	16% 14% 37% 26% 6% 1	760
	21st to end	Night	22% 13% 34% 25% 6%	930
December	1st to 10th	Night	19% 12% 39% 25% 5% 1	950
	11th to 20th	Night	23% 10% 32% 28% 6%	950
	21st to end	Night	24% 17% 34% 22% 3	1045

Page generated at 2024-11-03 01:11:15. Version ac07

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