Fakahatchee Strand Preserve
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Fakahatchee Strand Preserve clear sky chart from 2005-11-06 to 2026-10-29.

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	6% 5% 2 7% 6% 6% 6% 5% 8% 10% 39%	148344
	Night	7% 5% 2 7% 5% 5% 5% 5% 7% 10% 43%	143733
Transparency	Day	38% 6% 19% 22% 12% 4	152064
	Night	37% 6% 19% 22% 13% 4	148085
Seeing	Day	7% 5% 18% 27% 24% 19%	18527
	Night	8% 4 17% 32% 28% 11%	28581

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	6% 4 2 4 3 3 3 3 6% 9% 56%	5258
	11th to 20th	Day	14% 6% 3 8% 5% 5% 5% 4 7% 9% 34%	5280
	21st to end	Day	11% 6% 2 7% 5% 5% 5% 4 6% 7% 43%	6179
February	1st to 10th	Day	8% 6% 2 6% 4 5% 5% 4 6% 7% 47%	2100
	11th to 20th	Day	6% 3 1 4 4 3 4 4 6% 8% 57%	2068
	21st to end	Day	5% 4 2 5% 5% 5% 5% 4 6% 9% 51%	1903
March	1st to 10th	Day	4 3 2 7% 5% 5% 5% 5% 8% 9% 47%	5045
	11th to 20th	Day	3 3 1 3 3 3 3 3 6% 9% 64%	5090
	21st to end	Day	8% 4 2 5% 4 4 5% 4 6% 8% 49%	5586
April	1st to 10th	Day	4 4 2 6% 5% 4 5% 4 7% 10% 50%	2310
	11th to 20th	Day	5% 4 2 6% 6% 5% 5% 5% 6% 9% 46%	2296
	21st to end	Day	5% 3 2 6% 4 5% 6% 5% 6% 9% 49%	2520
May	1st to 10th	Day	4 2 1 3 4 4 5% 4 6% 10% 57%	7021
	11th to 20th	Day	4 4 2 6% 5% 6% 5% 5% 6% 9% 49%	7565
	21st to end	Day	4 4 2 6% 6% 6% 7% 5% 8% 12% 40%	8391
June	1st to 10th	Day	13% 9% 3 11% 8% 8% 9% 6% 8% 8% 17%	2730
	11th to 20th	Day	9% 7% 3 10% 8% 8% 8% 7% 8% 10% 21%	2730
	21st to end	Day	7% 7% 3 10% 8% 8% 8% 7% 9% 9% 22%	2730
July	1st to 10th	Day	5% 5% 3 10% 8% 8% 8% 6% 9% 13% 25%	7680
	11th to 20th	Day	4 4 3 10% 8% 8% 9% 8% 10% 13% 24%	7680
	21st to end	Day	3 3 2 7% 7% 7% 8% 6% 11% 15% 31%	8340
August	1st to 10th	Day	4 6% 3 11% 9% 8% 9% 7% 9% 12% 23%	6014
	11th to 20th	Day	3 3 2 7% 6% 7% 8% 6% 9% 13% 36%	5280
	21st to end	Day	5% 5% 2 8% 7% 7% 8% 7% 10% 15% 27%	5566
September	1st to 10th	Day	7% 6% 3 10% 8% 9% 9% 6% 10% 11% 22%	2310
	11th to 20th	Day	8% 6% 3 11% 8% 8% 8% 7% 9% 9% 22%	2310
	21st to end	Day	10% 7% 4 11% 8% 8% 7% 6% 8% 9% 22%	2310
October	1st to 10th	Day	8% 7% 3 10% 7% 7% 7% 6% 7% 10% 28%	2290
	11th to 20th	Day	7% 6% 2 8% 7% 6% 7% 5% 7% 8% 37%	2100
	21st to end	Day	8% 6% 3 6% 5% 5% 5% 4 7% 9% 42%	2280
November	1st to 10th	Day	6% 6% 3 6% 6% 5% 5% 5% 6% 9% 45%	2057
	11th to 20th	Day	8% 5% 1 7% 6% 4 5% 5% 7% 8% 43%	2100
	21st to end	Day	6% 4 2 6% 5% 5% 5% 4 7% 8% 48%	2100
December	1st to 10th	Day	5% 3 2 4 3 3 4 3 5% 6% 61%	3097
	11th to 20th	Day	8% 6% 2 6% 5% 5% 5% 5% 7% 10% 42%	3463
	21st to end	Day	10% 6% 2 8% 6% 6% 6% 6% 7% 10% 34%	4565
January	1st to 10th	Night	6% 4 2 5% 4 4 4 3 6% 9% 54%	7635
	11th to 20th	Night	15% 9% 4 8% 5% 5% 5% 4 5% 7% 34%	7680
	21st to end	Night	11% 5% 2 7% 4 4 4 4 6% 8% 45%	7984
February	1st to 10th	Night	8% 6% 2 6% 4 4 4 4 5% 8% 49%	2520
	11th to 20th	Night	7% 4 2 4 3 3 5% 3 5% 9% 55%	2436
	21st to end	Night	4 3 2 4 3 3 4 3 4 8% 60%	1903
March	1st to 10th	Night	5% 5% 2 6% 5% 4 5% 4 6% 7% 51%	5028
	11th to 20th	Night	5% 3 1 4 3 3 3 3 6% 8% 60%	5090
	21st to end	Night	8% 5% 2 6% 5% 4 5% 4 6% 8% 48%	5588
April	1st to 10th	Night	4 4 1 4 4 4 4 4 6% 9% 55%	2310
	11th to 20th	Night	5% 3 1 5% 4 3 4 4 6% 10% 55%	2270
	21st to end	Night	6% 4 2 4 4 4 4 4 5% 8% 54%	2100
May	1st to 10th	Night	7% 4 2 5% 4 4 4 4 7% 9% 52%	5833
	11th to 20th	Night	5% 4 2 5% 4 4 5% 3 6% 8% 54%	5334
	21st to end	Night	6% 5% 2 5% 4 4 5% 5% 8% 11% 46%	5761
June	1st to 10th	Night	12% 9% 3 9% 5% 6% 6% 5% 7% 10% 29%	1890
	11th to 20th	Night	7% 6% 3 7% 7% 5% 7% 5% 9% 12% 32%	1890
	21st to end	Night	5% 6% 4 9% 6% 6% 7% 6% 8% 13% 30%	1890
July	1st to 10th	Night	5% 6% 3 10% 8% 7% 7% 6% 10% 12% 26%	5278
	11th to 20th	Night	4 5% 3 9% 6% 7% 7% 6% 10% 14% 29%	5277
	21st to end	Night	4 4 2 7% 5% 5% 7% 6% 10% 12% 37%	5736
August	1st to 10th	Night	5% 6% 3 9% 6% 7% 7% 6% 9% 12% 28%	4135
	11th to 20th	Night	5% 5% 3 7% 6% 6% 6% 5% 8% 11% 39%	4709
	21st to end	Night	4 5% 3 8% 7% 7% 8% 8% 11% 14% 26%	5559
September	1st to 10th	Night	6% 5% 2 8% 6% 7% 7% 7% 10% 13% 29%	2310
	11th to 20th	Night	8% 7% 3 9% 6% 7% 6% 6% 8% 12% 30%	2310
	21st to end	Night	8% 8% 4 10% 7% 7% 7% 6% 7% 10% 27%	2310
October	1st to 10th	Night	9% 7% 3 10% 5% 6% 6% 4 7% 10% 33%	2326
	11th to 20th	Night	8% 6% 3 6% 5% 5% 4 4 6% 9% 44%	2520
	21st to end	Night	10% 5% 3 6% 4 5% 4 4 5% 8% 44%	2737
November	1st to 10th	Night	8% 5% 2 5% 4 4 4 3 6% 9% 49%	2461
	11th to 20th	Night	7% 6% 2 5% 5% 4 5% 4 6% 10% 47%	2520
	21st to end	Night	7% 6% 2 6% 5% 4 4 4 6% 8% 49%	2520
December	1st to 10th	Night	5% 4 1 4 3 3 3 4 5% 8% 60%	4298
	11th to 20th	Night	11% 5% 2 5% 4 3 4 4 6% 8% 47%	4952
	21st to end	Night	10% 8% 3 9% 5% 5% 6% 4 7% 9% 34%	6633

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	25% 2 8% 35% 23% 7%	5259
	11th to 20th	Day	47% 3 13% 21% 10% 5%	5280
	21st to end	Day	41% 2 7% 27% 16% 7%	6179
February	1st to 10th	Day	34% 4 9% 24% 20% 10%	2100
	11th to 20th	Day	24% 4 8% 28% 26% 10%	2078
	21st to end	Day	29% 4 9% 21% 27% 11%	1903
March	1st to 10th	Day	32% 2 12% 23% 24% 6%	5045
	11th to 20th	Day	19% 2 14% 27% 20% 18%	5090
	21st to end	Day	33% 2 8% 28% 20% 9%	5586
April	1st to 10th	Day	28% 3 15% 30% 19% 5%	2310
	11th to 20th	Day	33% 4 13% 23% 19% 8%	2296
	21st to end	Day	31% 3 11% 24% 25% 6%	2520
May	1st to 10th	Day	23% 3 15% 37% 20% 2	7053
	11th to 20th	Day	32% 4 15% 35% 12% 3	7569
	21st to end	Day	36% 5% 21% 29% 8%	8405
June	1st to 10th	Day	61% 6% 17% 13% 3	2730
	11th to 20th	Day	53% 9% 22% 14% 2	2730
	21st to end	Day	54% 8% 25% 12% 1	2730
July	1st to 10th	Day	47% 10% 34% 9%	7615
	11th to 20th	Day	47% 9% 33% 11%	7611
	21st to end	Day	38% 10% 33% 18% 1	8156
August	1st to 10th	Day	51% 10% 28% 10% 1	6001
	11th to 20th	Day	36% 8% 29% 23% 5%	5318
	21st to end	Day	43% 10% 39% 7% 1	5566
September	1st to 10th	Day	52% 12% 25% 11% 1	2310
	11th to 20th	Day	52% 12% 21% 12% 3	2310
	21st to end	Day	56% 9% 17% 12% 5% 1	2310
October	1st to 10th	Day	53% 7% 17% 13% 7% 2	3667
	11th to 20th	Day	41% 5% 18% 19% 14% 3	3340
	21st to end	Day	35% 5% 9% 26% 21% 6%	3618
November	1st to 10th	Day	35% 5% 10% 20% 20% 10%	2057
	11th to 20th	Day	36% 5% 9% 22% 20% 9%	2100
	21st to end	Day	32% 4 11% 22% 23% 7%	2100
December	1st to 10th	Day	24% 3 13% 28% 23% 10%	3097
	11th to 20th	Day	35% 4 12% 22% 21% 6%	3460
	21st to end	Day	44% 4 16% 19% 15% 3	4565
January	1st to 10th	Night	28% 2 9% 34% 22% 5%	7636
	11th to 20th	Night	50% 3 15% 19% 10% 3	7680
	21st to end	Night	38% 3 9% 29% 17% 5%	7984
February	1st to 10th	Night	33% 3 11% 25% 20% 8%	2520
	11th to 20th	Night	27% 3 10% 28% 22% 9%	2437
	21st to end	Night	22% 4 10% 23% 32% 9%	1903
March	1st to 10th	Night	33% 3 11% 22% 25% 6%	5028
	11th to 20th	Night	24% 2 18% 24% 20% 13%	5090
	21st to end	Night	34% 3 11% 25% 22% 6%	5588
April	1st to 10th	Night	25% 4 17% 33% 16% 5%	2310
	11th to 20th	Night	25% 4 15% 25% 23% 7%	2270
	21st to end	Night	27% 4 12% 29% 23% 4	2100
May	1st to 10th	Night	30% 3 19% 34% 12% 2	5863
	11th to 20th	Night	29% 4 21% 32% 12% 2	5335
	21st to end	Night	32% 5% 25% 27% 10%	5771
June	1st to 10th	Night	50% 7% 21% 19% 3	1890
	11th to 20th	Night	42% 10% 27% 19% 2	1890
	21st to end	Night	44% 11% 30% 13% 2	1890
July	1st to 10th	Night	48% 11% 32% 8%	5235
	11th to 20th	Night	43% 12% 37% 9%	5226
	21st to end	Night	36% 11% 34% 18% 2	5606
August	1st to 10th	Night	45% 9% 33% 11% 1	4124
	11th to 20th	Night	36% 11% 31% 17% 5%	4737
	21st to end	Night	45% 13% 37% 5% 1	5559
September	1st to 10th	Night	41% 14% 32% 11% 1	2310
	11th to 20th	Night	46% 13% 26% 13% 2	2310
	21st to end	Night	50% 10% 21% 14% 5%	2310
October	1st to 10th	Night	54% 8% 17% 13% 6% 2	3729
	11th to 20th	Night	40% 5% 18% 19% 16% 2	4019
	21st to end	Night	36% 4 10% 27% 19% 4	4349
November	1st to 10th	Night	32% 5% 11% 21% 21% 9%	2461
	11th to 20th	Night	34% 5% 8% 26% 21% 7%	2520
	21st to end	Night	32% 5% 11% 22% 23% 6%	2520
December	1st to 10th	Night	23% 4 13% 36% 16% 10%	4298
	11th to 20th	Night	34% 4 11% 26% 20% 6%	4954
	21st to end	Night	46% 4 17% 16% 15% 3	6633

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	8% 8% 41% 25% 15% 3	330
	11th to 20th	Day	12% 13% 36% 30% 9% 1	330
	21st to end	Day	11% 12% 43% 26% 7%	363
February	1st to 10th	Day	6% 10% 30% 35% 16% 3	330
	11th to 20th	Day	5% 7% 30% 41% 14% 3	350
	21st to end	Day	3 8% 28% 36% 22% 3	446
March	1st to 10th	Day	4 9% 34% 36% 15% 2	540
	11th to 20th	Day	7% 9% 30% 29% 21% 3	540
	21st to end	Day	5% 5% 29% 32% 24% 4	594
April	1st to 10th	Day	3 7% 33% 36% 16% 5%	540
	11th to 20th	Day	5% 7% 28% 33% 19% 8%	532
	21st to end	Day	4 5% 23% 35% 25% 7%	540
May	1st to 10th	Day	5% 2 18% 37% 29% 10%	543
	11th to 20th	Day	7% 6% 18% 29% 24% 15%	567
	21st to end	Day	8% 2 9% 28% 32% 22%	617
June	1st to 10th	Day	12% 3 9% 27% 27% 21%	570
	11th to 20th	Day	10% 3 8% 21% 25% 34%	570
	21st to end	Day	5% 2 3 14% 26% 50%	570
July	1st to 10th	Day	4 3 2 11% 31% 50%	565
	11th to 20th	Day	5% 1 3 16% 33% 42%	564
	21st to end	Day	5% 2 3 18% 28% 43%	620
August	1st to 10th	Day	5% 2 4 14% 30% 45%	566
	11th to 20th	Day	3 1 3 14% 30% 49%	559
	21st to end	Day	7% 2 6% 20% 28% 37%	627
September	1st to 10th	Day	8% 3 5% 14% 28% 42%	570
	11th to 20th	Day	6% 2 5% 18% 31% 39%	570
	21st to end	Day	9% 3 9% 20% 31% 29%	570
October	1st to 10th	Day	8% 4 14% 32% 31% 12%	570
	11th to 20th	Day	7% 4 14% 35% 28% 11%	570
	21st to end	Day	7% 6% 23% 35% 23% 7%	615
November	1st to 10th	Day	9% 7% 19% 34% 24% 7%	535
	11th to 20th	Day	9% 5% 24% 31% 25% 6%	540
	21st to end	Day	3 4 29% 36% 23% 5%	540
December	1st to 10th	Day	9% 8% 29% 31% 21% 2	381
	11th to 20th	Day	7% 10% 33% 32% 15% 3	330
	21st to end	Day	8% 7% 30% 34% 17% 4	363
January	1st to 10th	Night	8% 5% 25% 44% 18% 1	840
	11th to 20th	Night	10% 7% 29% 40% 14%	840
	21st to end	Night	10% 8% 31% 40% 11%	924
February	1st to 10th	Night	10% 7% 29% 40% 14% 1	840
	11th to 20th	Night	8% 5% 26% 42% 18% 1	823
	21st to end	Night	5% 5% 23% 48% 18%	692
March	1st to 10th	Night	3 6% 30% 44% 16%	840
	11th to 20th	Night	7% 5% 27% 44% 16% 1	840
	21st to end	Night	6% 5% 28% 42% 17% 1	924
April	1st to 10th	Night	4 5% 26% 43% 21% 1	840
	11th to 20th	Night	6% 4 29% 40% 19% 1	831
	21st to end	Night	7% 4 25% 43% 20% 1	840
May	1st to 10th	Night	4 2 18% 45% 27% 3	840
	11th to 20th	Night	7% 2 12% 45% 29% 5%	658
	21st to end	Night	6% 3 7% 32% 44% 8%	683
June	1st to 10th	Night	13% 3 6% 22% 43% 12%	630
	11th to 20th	Night	8% 2 4 13% 44% 29%	630
	21st to end	Night	4 2 2 11% 46% 35%	630
July	1st to 10th	Night	5% 2 1 7% 45% 40%	615
	11th to 20th	Night	4 1 1 8% 45% 41%	612
	21st to end	Night	4 2 3 9% 38% 44%	690
August	1st to 10th	Night	7% 2 2 9% 43% 37%	627
	11th to 20th	Night	5% 2 1 9% 44% 38%	751
	21st to end	Night	9% 2 5% 16% 39% 28%	924
September	1st to 10th	Night	7% 3 4 12% 43% 31%	840
	11th to 20th	Night	10% 2 5% 17% 42% 24%	840
	21st to end	Night	11% 3 6% 21% 39% 19%	840
October	1st to 10th	Night	12% 3 12% 35% 31% 8%	840
	11th to 20th	Night	10% 4 12% 35% 29% 10%	840
	21st to end	Night	12% 3 20% 36% 24% 5%	913
November	1st to 10th	Night	9% 4 23% 37% 25% 3	820
	11th to 20th	Night	8% 2 23% 39% 25% 3	840
	21st to end	Night	9% 4 22% 41% 24% 1	840
December	1st to 10th	Night	7% 4 22% 40% 26% 2	840
	11th to 20th	Night	10% 5% 22% 39% 22% 3	840
	21st to end	Night	9% 5% 23% 39% 21% 2	924

Page generated at 2026-10-26 04:37:46. Version ac07

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