Dyersburg
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Dyersburg clear sky chart from 2005-11-06 to 2025-01-07.

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% 2 6% 4 4 4 4 5% 7% 44%	104666
	Night	13% 6% 2 5% 4 4 4 3 5% 7% 47%	104401
Transparency	Day	38% 5% 10% 24% 19% 4	108354
	Night	36% 4 9% 25% 21% 5%	108842
Seeing	Day	15% 7% 22% 25% 21% 10%	15575
	Night	15% 6% 25% 32% 19% 2	25432

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	14% 11% 3 9% 4 3 3 3 3 5% 41%	2575
	11th to 20th	Day	19% 8% 2 7% 4 4 3 2 3 5% 42%	2817
	21st to end	Day	24% 11% 3 5% 3 3 3 3 4 6% 37%	3135
February	1st to 10th	Day	19% 10% 3 6% 4 4 3 3 5% 6% 38%	1858
	11th to 20th	Day	19% 9% 3 7% 4 3 3 3 5% 4 39%	1848
	21st to end	Day	22% 10% 3 6% 5% 4 4 3 4 5% 34%	1570
March	1st to 10th	Day	19% 14% 3 7% 4 3 3 3 4 5% 35%	3120
	11th to 20th	Day	14% 7% 2 6% 4 3 4 3 4 6% 46%	3413
	21st to end	Day	13% 6% 3 7% 5% 4 5% 4 5% 7% 41%	4096
April	1st to 10th	Day	12% 6% 2 6% 5% 3 5% 3 5% 7% 46%	2280
	11th to 20th	Day	16% 6% 2 7% 4 5% 4 4 5% 6% 43%	2254
	21st to end	Day	15% 7% 3 6% 5% 4 4 3 5% 7% 42%	2280
May	1st to 10th	Day	12% 6% 3 7% 6% 5% 5% 4 7% 9% 36%	3822
	11th to 20th	Day	14% 7% 2 6% 5% 4 5% 4 7% 9% 37%	4081
	21st to end	Day	9% 7% 3 8% 5% 5% 5% 4 7% 8% 38%	4694
June	1st to 10th	Day	8% 5% 3 6% 4 5% 5% 5% 7% 9% 43%	2660
	11th to 20th	Day	4 3 1 5% 5% 5% 6% 5% 7% 10% 48%	2660
	21st to end	Day	4 4 2 5% 5% 5% 5% 6% 7% 10% 48%	2660
July	1st to 10th	Day	6% 5% 2 7% 5% 6% 6% 5% 8% 10% 40%	4440
	11th to 20th	Day	7% 4 2 5% 4 4 4 5% 7% 12% 46%	4440
	21st to end	Day	12% 9% 4 9% 6% 5% 5% 5% 6% 7% 33%	4480
August	1st to 10th	Day	4 3 1 3 3 3 4 4 7% 10% 59%	3795
	11th to 20th	Day	9% 5% 2 5% 4 4 5% 4 6% 9% 47%	3729
	21st to end	Day	6% 4 1 4 4 3 4 4 5% 8% 58%	4180
September	1st to 10th	Day	10% 5% 2 5% 4 5% 5% 4 6% 8% 46%	2280
	11th to 20th	Day	13% 6% 2 5% 4 4 4 3 5% 7% 47%	2196
	21st to end	Day	11% 6% 2 5% 3 3 4 4 4 6% 52%	2090
October	1st to 10th	Day	9% 4 2 5% 3 3 3 3 4 6% 60%	2012
	11th to 20th	Day	12% 6% 2 4 3 3 3 3 4 6% 54%	1900
	21st to end	Day	19% 6% 1 4 3 2 3 3 5% 5% 50%	2071
November	1st to 10th	Day	11% 5% 2 5% 3 3 2 3 4 5% 56%	1762
	11th to 20th	Day	14% 6% 2 5% 3 3 3 3 4 6% 51%	1800
	21st to end	Day	18% 6% 2 7% 3 4 4 3 4 5% 44%	1800
December	1st to 10th	Day	15% 9% 2 6% 4 3 4 2 4 5% 47%	2878
	11th to 20th	Day	17% 8% 3 7% 4 4 4 3 5% 5% 41%	3008
	21st to end	Day	17% 11% 4 8% 5% 5% 5% 3 5% 6% 32%	3982
January	1st to 10th	Night	19% 7% 2 6% 3 3 4 3 4 5% 44%	4513
	11th to 20th	Night	17% 7% 3 7% 5% 3 4 3 3 5% 44%	4151
	21st to end	Night	25% 8% 2 4 2 2 3 2 4 4 43%	4532
February	1st to 10th	Night	19% 10% 4 7% 4 3 3 3 5% 6% 38%	2318
	11th to 20th	Night	18% 8% 2 7% 4 4 4 3 4 4 42%	2218
	21st to end	Night	20% 7% 2 6% 4 4 4 4 4 6% 40%	1884
March	1st to 10th	Night	21% 10% 3 6% 3 4 4 3 4 4 39%	3733
	11th to 20th	Night	14% 7% 3 5% 4 3 4 3 3 5% 50%	3562
	21st to end	Night	12% 6% 3 7% 5% 5% 4 4 5% 6% 42%	3533
April	1st to 10th	Night	10% 5% 2 5% 4 4 4 4 6% 7% 48%	1900
	11th to 20th	Night	16% 5% 2 5% 3 3 3 3 5% 7% 47%	1875
	21st to end	Night	14% 6% 3 6% 4 3 3 3 5% 7% 45%	1900
May	1st to 10th	Night	18% 7% 2 6% 3 3 4 3 4 8% 42%	3071
	11th to 20th	Night	12% 7% 2 6% 4 4 4 3 6% 7% 45%	2812
	21st to end	Night	8% 5% 2 7% 5% 5% 6% 5% 7% 10% 42%	2852
June	1st to 10th	Night	8% 6% 2 5% 5% 6% 4 4 6% 8% 45%	1520
	11th to 20th	Night	4 3 1 4 4 3 5% 3 5% 9% 58%	1520
	21st to end	Night	3 2 1 4 5% 4 5% 5% 8% 12% 52%	1520
July	1st to 10th	Night	6% 4 2 5% 4 5% 5% 5% 8% 11% 45%	2530
	11th to 20th	Night	4 4 2 5% 4 4 3 4 6% 11% 53%	2530
	21st to end	Night	9% 9% 4 9% 4 5% 4 3 6% 8% 39%	3064
August	1st to 10th	Night	2 2 1 4 3 4 4 3 6% 9% 63%	3132
	11th to 20th	Night	5% 3 2 5% 4 4 4 4 7% 11% 53%	3100
	21st to end	Night	4 3 1 4 3 3 4 3 6% 9% 59%	3476
September	1st to 10th	Night	9% 4 2 5% 3 3 4 3 5% 8% 54%	1900
	11th to 20th	Night	10% 5% 2 5% 4 2 4 3 5% 7% 52%	1963
	21st to end	Night	9% 5% 1 4 3 2 3 3 5% 7% 57%	2090
October	1st to 10th	Night	8% 3 1 4 3 2 3 3 5% 7% 61%	2164
	11th to 20th	Night	13% 5% 2 4 2 4 3 2 4 4 58%	2280
	21st to end	Night	17% 6% 2 4 3 3 3 3 4 5% 51%	2526
November	1st to 10th	Night	12% 5% 2 4 3 3 3 2 4 6% 55%	2536
	11th to 20th	Night	12% 4 1 5% 4 3 3 3 5% 6% 53%	2600
	21st to end	Night	14% 6% 2 5% 4 3 3 3 4 6% 49%	2600
December	1st to 10th	Night	18% 6% 2 5% 3 3 3 2 4 5% 49%	4301
	11th to 20th	Night	18% 8% 2 5% 4 3 3 3 4 5% 44%	5199
	21st to end	Night	19% 9% 4 7% 4 5% 4 3 5% 5% 36%	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	46% 3 7% 23% 18% 2	2576
	11th to 20th	Day	45% 4 9% 24% 17% 1	2817
	21st to end	Day	50% 3 8% 21% 16% 2	3135
February	1st to 10th	Day	48% 4 9% 23% 14% 2	1858
	11th to 20th	Day	49% 4 8% 20% 15% 4	1858
	21st to end	Day	53% 4 8% 16% 14% 5%	1570
March	1st to 10th	Day	52% 4 7% 15% 15% 8%	3120
	11th to 20th	Day	40% 4 6% 28% 17% 5%	3413
	21st to end	Day	42% 4 11% 22% 19% 1	4096
April	1st to 10th	Day	37% 5% 10% 26% 20% 2	2280
	11th to 20th	Day	42% 5% 9% 22% 18% 5%	2254
	21st to end	Day	42% 4 9% 27% 17% 1	2280
May	1st to 10th	Day	42% 6% 14% 22% 14% 1	3857
	11th to 20th	Day	42% 6% 14% 23% 13% 1	4085
	21st to end	Day	39% 8% 12% 25% 14% 1	4707
June	1st to 10th	Day	35% 7% 14% 23% 20% 2	2660
	11th to 20th	Day	28% 7% 14% 29% 19% 4	2660
	21st to end	Day	28% 9% 15% 25% 20% 4	2660
July	1st to 10th	Day	36% 8% 15% 26% 13% 2	4371
	11th to 20th	Day	29% 7% 13% 35% 12% 3	4365
	21st to end	Day	49% 8% 11% 24% 8% 1	4339
August	1st to 10th	Day	19% 7% 18% 30% 24% 2	3782
	11th to 20th	Day	32% 7% 16% 25% 17% 3	3765
	21st to end	Day	24% 6% 11% 32% 24% 2	4179
September	1st to 10th	Day	33% 7% 11% 26% 18% 5%	2280
	11th to 20th	Day	38% 5% 8% 22% 23% 4	2196
	21st to end	Day	34% 4 8% 23% 25% 6%	2090
October	1st to 10th	Day	17% 3 6% 16% 42% 17%	3337
	11th to 20th	Day	21% 3 6% 22% 32% 15%	3140
	21st to end	Day	28% 4 4 27% 31% 7%	3397
November	1st to 10th	Day	32% 4 8% 26% 25% 6%	1762
	11th to 20th	Day	35% 3 6% 23% 26% 6%	1800
	21st to end	Day	43% 4 6% 22% 21% 4	1800
December	1st to 10th	Day	41% 4 6% 29% 19% 2	2878
	11th to 20th	Day	44% 4 10% 24% 15% 3	3005
	21st to end	Day	53% 5% 8% 23% 10% 1	3982
January	1st to 10th	Night	43% 4 6% 28% 17% 2	4513
	11th to 20th	Night	45% 3 7% 22% 19% 3	4151
	21st to end	Night	46% 3 8% 24% 17% 2	4532
February	1st to 10th	Night	49% 3 9% 18% 18% 2	2318
	11th to 20th	Night	46% 4 7% 21% 17% 5%	2219
	21st to end	Night	46% 4 8% 18% 18% 6%	1884
March	1st to 10th	Night	49% 4 7% 14% 17% 9%	3733
	11th to 20th	Night	38% 3 9% 23% 19% 9%	3562
	21st to end	Night	41% 4 9% 26% 19% 1	3533
April	1st to 10th	Night	34% 5% 10% 25% 21% 5%	1900
	11th to 20th	Night	37% 4 8% 22% 21% 8%	1875
	21st to end	Night	39% 5% 8% 26% 20% 3	1900
May	1st to 10th	Night	42% 6% 13% 24% 13% 2	3101
	11th to 20th	Night	38% 6% 15% 25% 15% 1	2813
	21st to end	Night	35% 8% 13% 27% 15% 2	2860
June	1st to 10th	Night	35% 6% 11% 21% 23% 3	1520
	11th to 20th	Night	22% 5% 14% 32% 21% 5%	1520
	21st to end	Night	23% 7% 17% 28% 19% 7%	1520
July	1st to 10th	Night	30% 8% 18% 30% 13% 2	2490
	11th to 20th	Night	24% 6% 13% 37% 16% 4	2482
	21st to end	Night	43% 7% 14% 23% 12%	2967
August	1st to 10th	Night	17% 5% 14% 39% 24% 1	3121
	11th to 20th	Night	23% 8% 16% 31% 20% 2	3130
	21st to end	Night	21% 6% 11% 34% 25% 3	3476
September	1st to 10th	Night	28% 5% 11% 27% 22% 7%	1900
	11th to 20th	Night	32% 5% 9% 22% 28% 4	1963
	21st to end	Night	27% 4 10% 25% 27% 6%	2090
October	1st to 10th	Night	14% 4 6% 17% 39% 20%	3606
	11th to 20th	Night	19% 2 4 17% 39% 19%	3779
	21st to end	Night	26% 3 6% 26% 26% 13%	4150
November	1st to 10th	Night	31% 4 7% 25% 27% 7%	2536
	11th to 20th	Night	31% 4 6% 23% 26% 10%	2600
	21st to end	Night	37% 3 7% 25% 23% 4	2600
December	1st to 10th	Night	39% 3 8% 26% 22% 3	4301
	11th to 20th	Night	43% 3 6% 25% 20% 3	5201
	21st to end	Night	49% 4 9% 24% 11% 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	24% 13% 37% 20% 4 1	288
	11th to 20th	Day	29% 15% 33% 19% 3 1	270
	21st to end	Day	22% 13% 43% 18% 5%	297
February	1st to 10th	Day	25% 14% 35% 18% 6% 2	270
	11th to 20th	Day	30% 17% 33% 16% 3	270
	21st to end	Day	33% 18% 32% 13% 4	225
March	1st to 10th	Day	24% 13% 34% 20% 7% 1	270
	11th to 20th	Day	23% 16% 37% 19% 4 1	270
	21st to end	Day	22% 14% 34% 21% 10%	463
April	1st to 10th	Day	18% 13% 32% 27% 10% 1	460
	11th to 20th	Day	20% 12% 32% 25% 10% 2	452
	21st to end	Day	18% 12% 33% 21% 13% 4	460
May	1st to 10th	Day	17% 11% 28% 29% 13% 3	463
	11th to 20th	Day	16% 3 22% 27% 21% 11%	487
	21st to end	Day	10% 4 19% 32% 22% 13%	656
June	1st to 10th	Day	9% 4 18% 25% 29% 16%	680
	11th to 20th	Day	5% 1 13% 34% 33% 13%	680
	21st to end	Day	5% 1 17% 34% 27% 15%	680
July	1st to 10th	Day	6% 1 11% 27% 30% 24%	671
	11th to 20th	Day	6% 3 10% 24% 35% 21%	668
	21st to end	Day	9% 1 8% 28% 33% 20%	739
August	1st to 10th	Day	8% 1 7% 27% 40% 18%	496
	11th to 20th	Day	14% 2 10% 25% 33% 15%	479
	21st to end	Day	11% 8% 19% 34% 28%	539
September	1st to 10th	Day	11% 1 8% 26% 36% 18%	490
	11th to 20th	Day	12% 1 10% 20% 37% 20%	490
	21st to end	Day	15% 4 14% 28% 26% 13%	490
October	1st to 10th	Day	9% 3 18% 32% 28% 10%	412
	11th to 20th	Day	13% 5% 34% 27% 14% 7%	300
	21st to end	Day	23% 10% 31% 21% 14% 2	330
November	1st to 10th	Day	14% 9% 28% 30% 15% 4	300
	11th to 20th	Day	11% 10% 36% 29% 13% 1	300
	21st to end	Day	22% 11% 29% 22% 12% 3	300
December	1st to 10th	Day	23% 16% 29% 23% 8% 1	300
	11th to 20th	Day	23% 12% 33% 20% 10% 1	300
	21st to end	Day	22% 19% 34% 21% 4	330
January	1st to 10th	Night	22% 8% 38% 27% 5%	981
	11th to 20th	Night	24% 12% 35% 24% 4	950
	21st to end	Night	22% 11% 37% 28% 3	1045
February	1st to 10th	Night	23% 10% 35% 27% 5%	798
	11th to 20th	Night	23% 11% 37% 26% 2	743
	21st to end	Night	23% 15% 36% 22% 3	628
March	1st to 10th	Night	19% 12% 33% 32% 4	760
	11th to 20th	Night	22% 9% 35% 28% 5% 1	626
	21st to end	Night	17% 9% 34% 29% 10%	627
April	1st to 10th	Night	13% 11% 37% 30% 9% 1	570
	11th to 20th	Night	19% 9% 28% 31% 12% 1	563
	21st to end	Night	14% 7% 35% 32% 11% 1	570
May	1st to 10th	Night	15% 7% 26% 38% 12% 2	570
	11th to 20th	Night	14% 3 22% 38% 22% 2	561
	21st to end	Night	6% 2 19% 40% 29% 4	617
June	1st to 10th	Night	9% 3 11% 42% 30% 5%	570
	11th to 20th	Night	4 1 10% 45% 38% 3	570
	21st to end	Night	4 12% 40% 39% 4	570
July	1st to 10th	Night	6% 1 8% 31% 45% 10%	555
	11th to 20th	Night	5% 1 7% 28% 48% 9%	552
	21st to end	Night	6% 2 7% 30% 44% 11%	624
August	1st to 10th	Night	4 1 5% 34% 50% 7%	567
	11th to 20th	Night	7% 1 7% 36% 43% 6%	564
	21st to end	Night	7% 5% 31% 47% 9%	627
September	1st to 10th	Night	10% 2 9% 32% 41% 6%	570
	11th to 20th	Night	12% 1 8% 33% 39% 7%	633
	21st to end	Night	11% 2 15% 34% 32% 5%	760
October	1st to 10th	Night	8% 3 16% 37% 33% 3	760
	11th to 20th	Night	17% 3 25% 34% 19% 1	760
	21st to end	Night	20% 6% 27% 33% 14% 1	836
November	1st to 10th	Night	14% 5% 28% 36% 16% 1	780
	11th to 20th	Night	13% 7% 34% 34% 12% 1	800
	21st to end	Night	18% 9% 30% 32% 10% 1	800
December	1st to 10th	Night	22% 8% 29% 34% 6%	825
	11th to 20th	Night	23% 8% 31% 31% 8%	1000
	21st to end	Night	25% 11% 32% 27% 5%	1100

Page generated at 2025-01-04 02:24:03. Version ac07

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