As of 08:06 EDT

Weather in Siam, TN

55°Current weather

Siam, Wednesday, 14 October, 08:06

Clear. Feels like 55°. High 84°, low 55°.

Pressure30.15 inHg
Wind0 mph N
Humidity100%
Visibility6.2 mi
Dew point55°

Monthly outlook for Siam, TN: average high 65.4°, average low 45.7°. That is 0.6° above the climate normal for October. Precipitation is expected on 4 days (about 1.0 inches), against a normal of 5 days and 1.7 inches. The warmest day looks like 15 October (84.8°), the coolest 24 October (34.6°).

65.4°/45.7°
Average high / low
+0.6°
Above normal
4 / 5
Wet days / normal
1.0 in
Precipitation this month

Ten-day blocks vs climate normal

PeriodForecast highNormalDifference
14 October – 23 October69.5°65.3°+2.3°
24 October – 2 November58.6°62.8°-2.3°
3 November – 12 Novemberat normal58.4°—

October records over 66 years

91.4°3 October 2019All-time high
22.5°27 October 1982All-time low

Climate normals and records are computed from the nearest reference point — Johnson City (13 mi).

Thu, 1585° / 60°0Clear
85 °Clear

Siam, Thursday, 15 October

Clear. High 85°, low 60°.

Pressure30.12 inHg
Wind2.8 mph SW
Humidity65%
Visibility6.2 mi
Dew point67°
Fri, 1679° / 57°0.21Rain
79 °Rain

Siam, Friday, 16 October

Rain. High 79°, low 57°.

Pressure29.94 inHg
Wind11.7 mph SW
Humidity59%
Visibility6.2 mi
Dew point61°
Sat, 1755° / 44°0.13Light rain
55 °Light rain

Siam, Saturday, 17 October

Light rain. High 55°, low 44°.

Pressure30.30 inHg
Wind13.3 mph N
Humidity62%
Visibility6.2 mi
Dew point41°
Sun, 1862° / 39°0Clear
62 °Clear

Siam, Sunday, 18 October

Clear. High 62°, low 39°.

Pressure30.47 inHg
Wind9.6 mph E
Humidity32%
Visibility—
Dew point29°
Mon, 1965° / 38°0Clear
65 °Clear

Siam, Monday, 19 October

Clear. High 65°, low 38°.

Pressure30.42 inHg
Wind4.4 mph SE
Humidity39%
Visibility—
Dew point35°
Tue, 2074° / 51°0Overcast
74 °Overcast

Siam, Tuesday, 20 October

Overcast. High 74°, low 51°.

Pressure30.21 inHg
Wind4.3 mph SE
Humidity43%
Visibility—
Dew point47°
Wed, 2171° / 55°0.3Light rain
71 °Light rain

Siam, Wednesday, 21 October

Light rain. High 71°, low 55°.

Pressure30.09 inHg
Wind3.7 mph SW
Humidity65%
Visibility—
Dew point56°
Thu, 2265° / 54°0.31Light rain
65 °Light rain

Siam, Thursday, 22 October

Light rain. High 65°, low 54°.

Pressure30.03 inHg
Wind4 mph W
Humidity79%
Visibility—
Dew point58°
Fri, 2355° / 39°0Mostly clear
55 °Mostly clear

Siam, Friday, 23 October

Mostly clear. High 55°, low 39°.

Pressure30.21 inHg
Wind7 mph N
Humidity34%
Visibility—
Dew point25°
Sat, 2458° / 35°0Mostly clear
58 °Mostly clear

Siam, Saturday, 24 October

Mostly clear. High 58°, low 35°.

Pressure30.15 inHg
Wind4.1 mph NW
Humidity31%
Visibility—
Dew point25°
Sun, 2555° / 42°0Overcast
55 °Overcast

Siam, Sunday, 25 October

Overcast. High 55°, low 42°.

Pressure30.03 inHg
Wind4 mph SW
Humidity49%
Visibility—
Dew point35°
Mon, 2657° / 42°0Light rain
57 °Light rain

Siam, Monday, 26 October

Light rain. High 57°, low 42°.

Pressure30.03 inHg
Wind9.4 mph W
Humidity46%
Visibility—
Dew point35°
Tue, 2759° / 39°0Clear
59 °Clear

Siam, Tuesday, 27 October

Clear. High 59°, low 39°.

Pressure29.94 inHg
Wind7.2 mph W
Humidity38%
Visibility—
Dew point31°
Wed, 2859° / 38°0Mostly clear
59 °Mostly clear

Siam, Wednesday, 28 October

Mostly clear. High 59°, low 38°.

Pressure29.97 inHg
Wind5.1 mph NW
Humidity36%
Visibility—
Dew point30°
Thu, 2963° / 44°0Overcast
63 °Overcast

Siam, Thursday, 29 October

Overcast. High 63°, low 44°.

Pressure29.85 inHg
Wind4.3 mph N
Humidity42%
Visibility—
Dew point37°
From day 17 onward the outlook is built from 60-year climate statistics
Fri, 3063° / 43°0.13Climate normal
63 °Climate normal

Siam, Friday, 30 October

Climate normal for this date — 60-year average.

Average high63°
Average low43°
Average precipitation0.13 in
Chance of precipitation28%
Record high77° (2024)
Record low28° (2017)
Sat, 3164° / 45°0.08Climate normal
64 °Climate normal

Siam, Saturday, 31 October

Climate normal for this date — 60-year average.

Average high64°
Average low45°
Average precipitation0.08 in
Chance of precipitation30%
Record high78° (2024)
Record low32° (1993)
Sun, 0163° / 45°0.09Climate normal
63 °Climate normal

Siam, Sunday, 1 November

Climate normal for this date — 60-year average.

Average high63°
Average low45°
Average precipitation0.09 in
Chance of precipitation35%
Record high78° (2016)
Record low28° (2023)
Mon, 0262° / 44°0.15Climate normal
62 °Climate normal

Siam, Monday, 2 November

Climate normal for this date — 60-year average.

Average high62°
Average low44°
Average precipitation0.15 in
Chance of precipitation35%
Record high78° (2004)
Record low24° (2023)
Tue, 0361° / 43°0.08Climate normal
61 °Climate normal

Siam, Tuesday, 3 November

Climate normal for this date — 60-year average.

Average high61°
Average low43°
Average precipitation0.08 in
Chance of precipitation27%
Record high77° (2003)
Record low24° (2014)
Wed, 0459° / 42°0.14Climate normal
59 °Climate normal

Siam, Wednesday, 4 November

Climate normal for this date — 60-year average.

Average high59°
Average low42°
Average precipitation0.14 in
Chance of precipitation37%
Record high77° (2003)
Record low25° (1966)
Thu, 0559° / 41°0.13Climate normal
59 °Climate normal

Siam, Thursday, 5 November

Climate normal for this date — 60-year average.

Average high59°
Average low41°
Average precipitation0.13 in
Chance of precipitation32%
Record high75° (2022)
Record low25° (1991)
Fri, 0659° / 41°0.06Climate normal
59 °Climate normal

Siam, Friday, 6 November

Climate normal for this date — 60-year average.

Average high59°
Average low41°
Average precipitation0.06 in
Chance of precipitation33%
Record high79° (2024)
Record low25° (1967)
Sat, 0759° / 41°0.14Climate normal
59 °Climate normal

Siam, Saturday, 7 November

Climate normal for this date — 60-year average.

Average high59°
Average low41°
Average precipitation0.14 in
Chance of precipitation32%
Record high77° (2024)
Record low26° (1967)
Sun, 0858° / 40°0.1Climate normal
58 °Climate normal

Siam, Sunday, 8 November

Climate normal for this date — 60-year average.

Average high58°
Average low40°
Average precipitation0.1 in
Chance of precipitation28%
Record high78° (2023)
Record low25° (1971)
Mon, 0959° / 40°0.09Climate normal
59 °Climate normal

Siam, Monday, 9 November

Climate normal for this date — 60-year average.

Average high59°
Average low40°
Average precipitation0.09 in
Chance of precipitation25%
Record high76° (2023)
Record low25° (1995)
Tue, 1058° / 40°0.13Climate normal
58 °Climate normal

Siam, Tuesday, 10 November

Climate normal for this date — 60-year average.

Average high58°
Average low40°
Average precipitation0.13 in
Chance of precipitation38%
Record high74° (2006)
Record low25° (2025)
Wed, 1157° / 39°0.14Climate normal
57 °Climate normal

Siam, Wednesday, 11 November

Climate normal for this date — 60-year average.

Average high57°
Average low39°
Average precipitation0.14 in
Chance of precipitation33%
Record high76° (2020)
Record low22° (2025)
Thu, 1256° / 39°0.18Climate normal
56 °Climate normal

Siam, Thursday, 12 November

Climate normal for this date — 60-year average.

Average high56°
Average low39°
Average precipitation0.18 in
Chance of precipitation37%
Record high71° (2003)
Record low23° (2019)

About the monthly outlook

How accurate is a 30-day forecast?

The first 16 days come from weather models — reliable for the first 3–5 days and progressively less so after that. Days 17 through 30 for Siam, TN are built from the climate normal, the 60-year average, so they show typical weather for those dates rather than a specific forecast.

What does "above normal" mean?

We compare the forecast against the climate normal for those exact calendar days, computed from 60 years of observations. The deviation shows how much the coming month differs from a typical one.

Where do the 66-year records come from?

They are real temperature extremes recorded in Siam, TN since 1960: the highest and lowest reading for each calendar date, with the year it happened.

How often is it updated?

The forecast portion refreshes every hour; the climate portion is based on long-term data and stays stable.