Fort Worth
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Fort Worth clear sky chart from 2005-11-06 to 2024-01-31.

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 TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(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

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
43%
24082
29%
74478
18%
24023
56%
24023
38%
40057

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 10thNight
34%
948
33%
2458
12%
946
48%
946
41%
1402
January11th to 20thNight
32%
950
31%
2470
9%
950
45%
950
35%
1444
January21st to endNight
32%
1043
33%
2711
12%
1043
44%
1043
35%
1618
February1st to 10thNight
27%
765
28%
2205
10%
765
41%
765
31%
1298
February11th to 20thNight
24%
704
24%
2098
9%
700
36%
700
29%
1251
February21st to endNight
20%
592
29%
1776
7%
592
38%
592
27%
1051
March1st to 10thNight
26%
542
28%
1982
12%
542
45%
542
25%
1123
March11th to 20thNight
28%
540
24%
1980
12%
540
43%
540
27%
1098
March21st to endNight
29%
594
28%
2178
13%
594
49%
594
29%
1141
April1st to 10thNight
27%
540
27%
1980
12%
540
48%
540
30%
996
April11th to 20thNight
28%
533
25%
1893
14%
533
46%
533
28%
1007
April21st to endNight
28%
540
30%
1625
14%
540
49%
540
37%
892
May1st to 10thNight
30%
540
28%
1620
14%
540
49%
540
33%
912
May11th to 20thNight
36%
531
21%
1594
14%
531
49%
531
35%
922
May21st to endNight
44%
583
24%
1745
17%
582
57%
582
38%
984
June1st to 10thNight
60%
540
24%
1620
21%
540
69%
540
47%
843
June11th to 20thNight
56%
540
28%
1620
22%
540
68%
540
54%
772
June21st to endNight
60%
540
26%
1620
25%
540
68%
540
47%
831
July1st to 10thNight
65%
525
24%
1575
22%
525
72%
525
45%
828
July11th to 20thNight
75%
522
33%
1566
32%
522
84%
522
63%
693
July21st to endNight
79%
591
32%
1673
33%
558
85%
558
57%
779
August1st to 10thNight
82%
537
39%
1601
39%
534
89%
534
69%
681
August11th to 20thNight
72%
534
35%
1600
35%
534
79%
534
47%
825
August21st to endNight
78%
594
30%
2062
34%
594
82%
594
45%
981
September1st to 10thNight
68%
540
25%
1980
28%
540
72%
540
38%
994
September11th to 20thNight
62%
540
25%
1980
25%
540
68%
540
32%
1080
September21st to endNight
66%
540
36%
1980
34%
540
74%
540
47%
890
October1st to 10thNight
57%
540
39%
1980
31%
540
69%
540
45%
895
October11th to 20thNight
48%
720
36%
2160
19%
720
60%
720
44%
1115
October21st to endNight
40%
792
34%
2376
18%
792
51%
792
39%
1280
November1st to 10thNight
44%
740
32%
2220
17%
740
56%
740
41%
1197
November11th to 20thNight
43%
912
33%
2432
14%
912
54%
912
46%
1315
November21st to endNight
32%
950
31%
2470
11%
950
45%
950
34%
1499
December1st to 10thNight
36%
950
34%
2470
12%
950
50%
950
38%
1460
December11th to 20thNight
31%
949
31%
2863
12%
948
43%
948
30%
1682
December21st to endNight
31%
1041
19%
4315
10%
1026
44%
1026
25%
2278

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 ForecastData
Points
Cloud CoverDay
10%42442445%7%53%
75081
Night
10%423323347%58%
75075
TransparencyDay
31%410%24%22%8%
74806
Night
28%49%23%25%12%
74870
SeeingDay
13%10%26%29%18%4
14042
Night
12%9%31%33%13%1
24090

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
12%6%23313335%58%
1707
11th to 20thDay
13%434423346%55%
1710
21st to endDay
15%6%13213346%55%
1872
February1st to 10thDay
14%6%35%42335%5%50%
1768
11th to 20thDay
15%7%35%5%23335%49%
1749
21st to endDay
20%8%2321232454%
1480
March1st to 10thDay
17%6%2442335%6%47%
1975
11th to 20thDay
15%6%24425%45%5%49%
1980
21st to endDay
12%42443445%5%51%
2178
April1st to 10thDay
10%6%25%5%3445%6%50%
1980
11th to 20thDay
12%5%25%425%45%7%49%
2016
21st to endDay
11%425%4345%5%7%50%
2330
May1st to 10thDay
13%5%25%42445%8%49%
2340
11th to 20thDay
12%5%25%435%5%6%7%45%
2302
21st to endDay
11%5%36%5%345%7%9%40%
2531
June1st to 10thDay
5%2245%35%6%6%10%54%
2340
11th to 20thDay
5%3244345%6%9%55%
2340
21st to endDay
6%2235%25%46%9%54%
2340
July1st to 10thDay
6%5%25%5%35%7%7%10%44%
2340
11th to 20thDay
321232445%8%64%
2340
21st to endDay
32145%36%6%7%11%52%
2546
August1st to 10thDay
21123345%6%9%64%
2328
11th to 20thDay
7%3245%35%6%6%9%51%
2301
21st to endDay
5%324435%5%6%9%54%
2288
September1st to 10thDay
8%42442345%8%55%
1980
11th to 20thDay
10%425%5%36%5%5%7%47%
1980
21st to endDay
8%31342445%7%59%
1980
October1st to 10thDay
5%31433345%7%62%
1962
11th to 20thDay
11%413323236%61%
1800
21st to endDay
13%42332233461%
1980
November1st to 10thDay
13%5%23323345%58%
1858
11th to 20thDay
7%314433346%62%
1744
21st to endDay
15%6%23322335%55%
1710
December1st to 10thDay
14%6%14323446%53%
1710
11th to 20thDay
15%7%35%424445%48%
2161
21st to endDay
18%5%24422345%51%
3135
January1st to 10thNight
11%324323346%60%
2458
11th to 20thNight
13%5%13412235%58%
2470
21st to endNight
14%5%24323245%57%
2711
February1st to 10thNight
14%5%25%423335%55%
2205
11th to 20thNight
15%6%24423335%52%
2098
21st to endNight
18%5%2332333453%
1776
March1st to 10thNight
14%435%42345%7%48%
1982
11th to 20thNight
14%424334446%51%
1980
21st to endNight
10%5%23423446%56%
2178
April1st to 10thNight
9%42332435%8%56%
1980
11th to 20thNight
14%324324447%54%
1893
21st to endNight
11%423422446%58%
1625
May1st to 10thNight
10%42442445%9%53%
1620
11th to 20thNight
10%425%43446%8%50%
1593
21st to endNight
10%3144335%7%10%51%
1745
June1st to 10thNight
3323425%5%5%10%59%
1620
11th to 20thNight
221331446%9%64%
1620
21st to endNight
23234245%6%10%59%
1620
July1st to 10thNight
4423425%5%6%11%54%
1620
11th to 20thNight
3112222248%73%
1620
21st to endNight
211332447%11%63%
1772
August1st to 10thNight
211111225%10%72%
1611
11th to 20thNight
5%4233235%6%10%59%
1600
21st to endNight
43134335%7%9%59%
2062
September1st to 10thNight
7%42443446%8%57%
1980
11th to 20thNight
11%425%32345%7%53%
1980
21st to endNight
6%31331345%8%63%
1980
October1st to 10thNight
6%323323347%65%
1980
11th to 20thNight
11%313322345%64%
2160
21st to endNight
15%323222235%62%
2376
November1st to 10thNight
10%42432333363%
2220
11th to 20thNight
6%42332335%7%62%
2432
21st to endNight
15%5%24323435%55%
2470
December1st to 10thNight
12%5%24323336%57%
2470
11th to 20thNight
12%6%24423446%53%
3036
21st to endNight
16%6%2332333456%
4532

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
30%36%22%29%9%
1708
11th to 20thDay
33%26%24%26%8%
1710
21st to endDay
32%36%19%28%12%
1872
February1st to 10thDay
38%37%19%21%12%
1768
11th to 20thDay
40%37%20%20%10%
1759
21st to endDay
38%2415%24%16%
1480
March1st to 10thDay
38%38%17%22%12%
1975
11th to 20thDay
38%49%18%23%8%
1980
21st to endDay
34%5%10%22%20%9%
2178
April1st to 10thDay
34%411%21%18%11%
1980
11th to 20thDay
36%49%21%20%10%
2016
21st to endDay
33%5%9%21%25%6%
2330
May1st to 10thDay
34%5%10%23%19%8%
2340
11th to 20thDay
38%5%13%22%20%3
2306
21st to endDay
39%6%14%24%15%2
2531
June1st to 10thDay
26%7%15%30%18%4
2340
11th to 20thDay
26%5%12%32%19%6%
2340
21st to endDay
26%5%12%26%26%5%
2340
July1st to 10thDay
32%8%17%28%14%2
2276
11th to 20thDay
18%6%13%35%22%5%
2271
21st to endDay
21%8%18%35%18%1
2405
August1st to 10thDay
16%6%14%34%27%3
2314
11th to 20thDay
28%7%16%27%20%2
2301
21st to endDay
24%7%13%32%20%4
2288
September1st to 10thDay
28%49%23%25%10%
1980
11th to 20thDay
36%6%10%20%20%8%
1980
21st to endDay
24%48%24%27%13%
1980
October1st to 10thDay
22%412%24%22%16%
1962
11th to 20thDay
27%36%18%27%19%
1800
21st to endDay
29%36%20%25%17%
1980
November1st to 10thDay
30%38%23%26%11%
1858
11th to 20thDay
25%39%22%30%12%
1744
21st to endDay
35%25%21%24%12%
1710
December1st to 10thDay
33%39%23%24%8%
1710
11th to 20thDay
39%47%15%26%10%
2159
21st to endDay
37%3424%22%10%
3135
January1st to 10thNight
28%26%21%29%13%
2458
11th to 20thNight
30%36%21%28%11%
2470
21st to endNight
32%2418%27%17%
2711
February1st to 10thNight
34%38%18%22%16%
2205
11th to 20thNight
36%37%17%26%11%
2098
21st to endNight
36%36%16%20%18%
1776
March1st to 10thNight
37%47%18%20%15%
1982
11th to 20thNight
33%5%11%16%25%10%
1980
21st to endNight
29%5%10%22%25%8%
2178
April1st to 10thNight
28%410%23%20%15%
1980
11th to 20thNight
31%411%19%20%15%
1893
21st to endNight
28%5%11%22%28%7%
1625
May1st to 10thNight
31%411%25%20%10%
1620
11th to 20thNight
31%5%16%25%20%4
1594
21st to endNight
28%6%17%27%19%3
1746
June1st to 10thNight
21%6%15%32%21%5%
1620
11th to 20thNight
17%5%14%35%22%8%
1620
21st to endNight
20%7%13%26%27%7%
1620
July1st to 10thNight
22%6%17%34%17%3
1575
11th to 20thNight
12%411%38%28%7%
1566
21st to endNight
14%5%19%36%23%3
1673
August1st to 10thNight
9%411%39%31%6%
1601
11th to 20thNight
22%5%14%31%23%6%
1600
21st to endNight
21%6%12%33%24%5%
2062
September1st to 10thNight
26%6%10%22%26%10%
1980
11th to 20thNight
31%6%12%19%21%11%
1980
21st to endNight
20%48%24%28%17%
1980
October1st to 10thNight
21%38%28%21%19%
1980
11th to 20thNight
24%28%17%26%22%
2160
21st to endNight
29%2417%28%20%
2376
November1st to 10thNight
28%36%20%27%15%
2220
11th to 20thNight
22%47%23%28%15%
2432
21st to endNight
34%37%16%28%13%
2470
December1st to 10thNight
31%27%24%24%12%
2470
11th to 20thNight
34%36%16%28%13%
3037
21st to endNight
33%36%18%26%14%
4532

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
21%24%31%19%5%
270
11th to 20thDay
22%27%33%13%41
270
21st to endDay
23%25%33%13%5%
294
February1st to 10thDay
22%21%40%15%21
240
11th to 20thDay
27%20%43%9%2
240
21st to endDay
33%27%31%6%3
198
March1st to 10thDay
25%28%31%14%2
240
11th to 20thDay
25%24%36%12%3
240
21st to endDay
16%25%45%10%3
264
April1st to 10thDay
18%26%35%18%4
240
11th to 20thDay
21%21%37%17%4
294
21st to endDay
15%19%40%19%6%1
590
May1st to 10thDay
16%13%40%25%5%1
603
11th to 20thDay
17%7%37%26%11%2
625
21st to endDay
13%9%33%28%14%3
679
June1st to 10thDay
4323%40%23%6%
630
11th to 20thDay
5%331%40%18%4
630
21st to endDay
4318%43%25%6%
630
July1st to 10thDay
6%314%41%28%9%
621
11th to 20thDay
2111%41%38%7%
618
21st to endDay
317%40%38%11%
684
August1st to 10thDay
119%45%36%8%
626
11th to 20thDay
9%210%38%34%7%
615
21st to endDay
427%35%36%15%
407
September1st to 10thDay
6%18%34%40%11%
270
11th to 20thDay
7%212%35%34%10%
270
21st to endDay
14%311%39%21%11%
270
October1st to 10thDay
35%31%37%20%4
270
11th to 20thDay
12%10%34%31%11%2
270
21st to endDay
25%9%32%23%9%1
297
November1st to 10thDay
21%13%33%24%7%2
270
11th to 20thDay
13%14%39%26%7%2
270
21st to endDay
24%21%31%19%41
270
December1st to 10thDay
20%17%34%19%9%2
270
11th to 20thDay
19%21%34%22%4
270
21st to endDay
23%20%36%16%4
297
January1st to 10thNight
13%12%37%31%7%
950
11th to 20thNight
18%16%31%29%6%
950
21st to endNight
16%15%33%30%6%
1043
February1st to 10thNight
18%16%36%25%41
765
11th to 20thNight
18%15%39%25%3
704
21st to endNight
22%16%40%21%2
592
March1st to 10thNight
16%15%39%25%4
542
11th to 20thNight
17%13%39%26%5%
540
21st to endNight
13%16%38%27%5%
594
April1st to 10thNight
11%18%41%25%5%
540
11th to 20thNight
15%15%38%28%4
533
21st to endNight
14%13%44%23%6%1
540
May1st to 10thNight
12%13%41%28%6%1
540
11th to 20thNight
12%6%40%29%11%2
531
21st to endNight
9%6%37%32%15%1
584
June1st to 10thNight
4327%42%21%3
540
11th to 20thNight
4234%47%12%1
540
21st to endNight
3228%39%26%3
540
July1st to 10thNight
422%40%30%3
525
11th to 20thNight
3117%50%27%2
522
21st to endNight
2112%57%27%2
591
August1st to 10thNight
2112%54%28%2
537
11th to 20thNight
7%113%44%30%5%
534
21st to endNight
429%44%35%6%
594
September1st to 10thNight
8%114%43%30%4
540
11th to 20thNight
13%113%37%33%3
540
21st to endNight
8%220%40%26%4
540
October1st to 10thNight
7%227%36%24%3
540
11th to 20thNight
12%8%29%34%16%1
720
21st to endNight
18%9%31%30%12%
792
November1st to 10thNight
12%6%35%34%13%1
740
11th to 20thNight
8%11%35%33%12%1
912
21st to endNight
19%12%34%24%9%1
950
December1st to 10thNight
15%12%34%32%6%
950
11th to 20thNight
19%10%34%31%6%
950
21st to endNight
18%12%35%28%6%
1045
Page generated at 2024-01-28 04:26:37. Version ac07

Copyright 2024 Attilla Danko


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