# xarray.Dataset.std

#### Dataset.std(dim=None, , skipna=None, ddof=0, keep_attrs=None, \*\*kwargs)[[source]](https://github.com/pydata/xarray/blob/v2026.09.0/xarray/core/_aggregations.py#L2081-L2184)

Reduce this Dataset’s data by applying `std` (i.e., standard deviation) along some dimension(s).

* **Parameters:**
  * **dim** ([`str`](https://docs.python.org/3/builtins/stdtypes.html#str), `Iterable` of `Hashable`, `"..."` or [`None`](https://docs.python.org/3/builtins/constants.html#None), *default*: [`None`](https://docs.python.org/3/builtins/constants.html#None)) – Name of dimension[s] along which to apply `std`. For e.g. `dim="x"`
    or `dim=["x", "y"]`. If “…” or None, will reduce over all dimensions.
  * **skipna** ([`bool`](https://docs.python.org/3/builtins/functions.html#bool) or [`None`](https://docs.python.org/3/builtins/constants.html#None), *optional*) – If True, skip missing values (as marked by NaN). By default, only
    skips missing values for float dtypes; other dtypes either do not
    have a sentinel missing value (int) or `skipna=True` has not been
    implemented (object, datetime64 or timedelta64).
  * **ddof** ([`int`](https://docs.python.org/3/builtins/functions.html#int), *default*: `0`) – “Delta Degrees of Freedom”: the divisor used in the calculation is `N - ddof`,
    where `N` represents the number of elements.
  * **keep_attrs** ([`bool`](https://docs.python.org/3/builtins/functions.html#bool) or [`None`](https://docs.python.org/3/builtins/constants.html#None), *optional*) – If True, `attrs` will be copied from the original
    object to the new one.  If False, the new object will be
    returned without attributes.
  * **\*\*kwargs** (`Any`) – Additional keyword arguments passed on to the appropriate array
    function for calculating `std` on this object’s data.
    These could include dask-specific kwargs like `split_every`.
* **Returns:**
  **reduced** ([`Dataset`](xarray.Dataset.html.md#xarray.Dataset)) – New Dataset with `std` applied to its data and the
  indicated dimension(s) removed

#### SEE ALSO
[`numpy.std`](https://numpy.org/doc/stable/reference/generated/numpy.std.html#numpy.std), [`dask.array.std`](https://docs.dask.org/en/latest/generated/dask.array.std.html#dask.array.std), [`DataArray.std`](xarray.DataArray.std.html.md#xarray.DataArray.std)

[Aggregation](../user-guide/computation.html.md#agg)
: User guide on reduction or aggregation operations.

### Notes

Non-numeric variables will be removed prior to reducing. datetime64 and timedelta64 dtypes are treated as numeric for aggregation operations.

### Examples

<div class="try_examples_button_container"><button class="try_examples_button" onclick="window.tryExamplesShowIframe('aaf505eb-2345-4369-9f88-01ef3b54a51d','e00734d4-8f40-433c-b2dd-a5498e4d6c4f','52f04f87-7567-4b45-89b8-4c93a7a7a4de','../lite/tree/../notebooks/index.html?path=baf539d8_cf6e_45d5_8418_e121307f8079.ipynb','None')">Try it in your browser!</button></div>
```pycon
>>> da = xr.DataArray(
...     np.array([1, 2, 3, 0, 2, np.nan]),
...     dims="time",
...     coords=dict(
...         time=("time", pd.date_range("2001-01-01", freq="ME", periods=6)),
...         labels=("time", np.array(["a", "b", "c", "c", "b", "a"])),
...     ),
... )
>>> ds = xr.Dataset(dict(da=da))
>>> ds
<xarray.Dataset> Size: 120B
Dimensions:  (time: 6)
Coordinates:
  * time     (time) datetime64[us] 48B 2001-01-31 2001-02-28 ... 2001-06-30
    labels   (time) <U1 24B 'a' 'b' 'c' 'c' 'b' 'a'
Data variables:
    da       (time) float64 48B 1.0 2.0 3.0 0.0 2.0 nan
```

```pycon
>>> ds.std()
<xarray.Dataset> Size: 8B
Dimensions:  ()
Data variables:
    da       float64 8B 1.02
```

Use `skipna` to control whether NaNs are ignored.

```pycon
>>> ds.std(skipna=False)
<xarray.Dataset> Size: 8B
Dimensions:  ()
Data variables:
    da       float64 8B nan
```

Specify `ddof=1` for an unbiased estimate.

```pycon
>>> ds.std(skipna=True, ddof=1)
<xarray.Dataset> Size: 8B
Dimensions:  ()
Data variables:
    da       float64 8B 1.14
```

<div id="52f04f87-7567-4b45-89b8-4c93a7a7a4de" class="try_examples_outer_iframe  hidden"><div class="try_examples_button_container"><button class="try_examples_button" onclick="window.tryExamplesHideIframe('aaf505eb-2345-4369-9f88-01ef3b54a51d','52f04f87-7567-4b45-89b8-4c93a7a7a4de')">Go Back</button><button class="try_examples_button" onclick="window.openInNewTab('aaf505eb-2345-4369-9f88-01ef3b54a51d','52f04f87-7567-4b45-89b8-4c93a7a7a4de')">Open In Tab</button></div><div id="e00734d4-8f40-433c-b2dd-a5498e4d6c4f" class="jupyterlite_sphinx_iframe_container"></div></div><script>document.addEventListener("DOMContentLoaded", function() {window.loadTryExamplesConfig("../try_examples.json");});</script>